1. A certain solid sample adsorbs 0.63 mg of CO when the pressure of the gas is 36.0 kPa and the temperature is 300 K. The mass of gas adsorbed when the pressure is 4.0 kPa and the temperature is 300 K is 0.21 mg. The Langmuir isotherm is known to describe the adsorption. Find the fractional coverage of the surface at the two pressures.

2. A certain solid sample adsorbs 0.44 mg of CO when the pressure of the gas is 26.0 kPa and the temperature is 300 K. The mass of gas adsorbed when the pressure is 3.0 kPa and the temperature is 300 K is 0.19 mg. The Langmuir isotherm is known to describe the adsorption. Find the fractional coverage of the surface at the two pressures.

Answers

Answer 1

Fractional coverage refers to the fraction or proportion of the surface of a solid sample that is covered or occupied by adsorbed molecules or atoms.

The answers are:

1. The fractional coverage of the surface at a pressure of 36.0 kPa is approximately 0.055.

The fractional coverage of the surface at a pressure of 4.0 kPa is approximately 0.001.

2. The fractional coverage of the surface at a pressure of 3.0 kPa is approximately 0.0006.

1. To find the fractional coverage of the surface at different pressures using the Langmuir isotherm equation, we can use the following formula:

θ = (P * m) / (P₀ * M * k * T)

Where:

θ is the fractional coverage of the surface.

P is the pressure of the gas.

m is the mass of the gas adsorbed.

P₀ is a reference pressure.

M is the molar mass of the gas.

k is the Boltzmann constant.

T is the temperature.

Let's calculate the fractional coverage for the given data.

For the first case:

P = 36.0 kPa

m = 0.63 mg

P₀ = 4.0 kPa

M = molar mass of CO = 28.01 g/mol

k = Boltzmann constant = 8.617333262145 x 10^(-5) eV/K

T = 300 K

θ₁ = (P * m) / (P₀ * M * k * T)

= (36.0 * 0.63) / (4.0 * 28.01 * 10^(-3) * 8.617333262145 x 10^(-5) * 300)

≈ 0.055

So, the fractional coverage of the surface at a pressure of 36.0 kPa is approximately 0.055.

Now, for the second case:

P = 4.0 kPa

m = 0.21 mg

P₀ = 36.0 kPa

M = molar mass of CO = 28.01 g/mol

k = Boltzmann constant = 8.617333262145 x 10^(-5) eV/K

T = 300 K

θ₂ = (P * m) / (P₀ * M * k * T)

= (4.0 * 0.21) / (36.0 * 28.01 * 10^(-3) * 8.617333262145 x 10^(-5) * 300)

≈ 0.001

So, the fractional coverage of the surface at a pressure of 4.0 kPa is approximately 0.001.

2. For the second set of data, we can follow the same steps:

P = 26.0 kPa

m = 0.44 mg

P₀ = 3.0 kPa

M = molar mass of CO = 28.01 g/mol

k = Boltzmann constant = 8.617333262145 x 10^(-5) eV/K

T = 300 K

θ₁ = (P * m) / (P₀ * M * k * T)

= (26.0 * 0.44) / (3.0 * 28.01 * 10^(-3) * 8.617333262145 x 10^(-5) * 300)

≈ 0.008

The fractional coverage of the surface at a pressure of 26.0 kPa is approximately 0.008.

Now, for the second case:

P = 3.0 kPa

m = 0.19 mg

P₀ = 26.0 kPa

M = molar mass of CO = 28.01 g/mol

k = Boltzmann constant = 8.617333262145 x 10^(-5) eV/K

T = 300 K

θ₂ = (P * m) / (P₀ * M * k * T)

= (3.0 * 0.19) / (26.0 * 28.01 * 10^(-3) * 8.617333262145 x 10^(-5) * 300)

≈ 0.0006

The fractional coverage of the surface at a pressure of 3.0 kPa is approximately 0.0006.

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Related Questions

Write the chemical equation for the base ionization of methylamine, CH3NH2. Write the Kb expression.

Answers

The chemical equation for the base ionization of methylamine (CH3NH2) is: CH3NH2 + H2O ⇌ CH3NH3+ + OH- and The Kb expression for methylamine can be written as: Kb = [CH3NH3+][OH-] / [CH3NH2]

The chemical equation for the base ionization of methylamine (CH3NH2) is: CH3NH2 + H2O ⇌ CH3NH3+ + OH- .The Kb expression for methylamine can be written as: Kb = [CH3NH3+][OH-] / [CH3NH2]. In this equation, [CH3NH3+] represents the concentration of the methylammonium ion, [OH-] represents the concentration of hydroxide ion, and [CH3NH2] represents the concentration of methylamine. Kb is the base dissociation constant, which quantifies the extent of ionization of the base in water. It provides information about the strength of the base and its ability to accept protons. The higher the value of Kb, the stronger the base.

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Your lab partner wrote the name for the compound pc13 as "phosphorus chlorine." explain why that is
incorrect and give the correct name of the compound.

Answers

The name phosphorus chlorine is incorrect because it does not tell us about the number of chlorine atom present in the chemical formula and the correct name of PCl₃ is phosphorus trichloride.

The chemical formula of a compound is a symbolic representation of its chemical composition.

Chemical formulae gives information about the elements that constitute the molecules of a compound and also about the ratio in which the atoms of these elements combine to form such molecules.

Every constituent component in a chemical formula is identified with its chemical symbol, along with the relative number of atoms that make up each element.

While naming a covalent compound, the number of the more electronegative atom is also included.

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Salinity can be calculated from all of the ions found in the water. The most commonly used is chlorine. If the chlorinity of a sample is determined to be 1.92%, what is the salinity

Answers

To calculate the salinity of a sample using chlorinity, we need to know the molar concentration of chloride ions (Cl-). We can find the molar concentration of chloride ions by multiplying the mass of chloride ions (in grams) by the molar mass of chloride ions (in grams per mole) and dividing by the volume (in liters) of the sample.

The molar mass of chloride ions is 35.45 g/mol.

We can also find the molar concentration of chloride ions by using the following formula:

Molar concentration of chloride ions (in mol/L) = Mass of chloride ions (in grams) / Volume of the sample (in liters)

Plugging in the values we know, we get:

Molar concentration of chloride ions (in mol/L) = 1.92 g / 0.003545 L

Molar concentration of chloride ions (in mol/L) = 55.38 mol/L

Therefore, the salinity of the sample can be calculated as:

Salinity of the sample = Molar concentration of chloride ions (in mol/L) / (1000/2)

Salinity of the sample = 55.38 mol/L / (1000/2)

Salinity of the sample = 27.69 g/L

Therefore, the salinity of the sample is 27.69 g/L.

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1.


a) If 1. 08 g of sodium sulfate reacts with an excess of phosphoric acid, how much sulfuric acid is produced? (0. 74577)


b) If 0. 726 g of sulfuric acid is produced in the laboratory experiment, what is the percent yield of sulfuric acid? (97. 3190)


2.


If 3. 2 moles of sodium sulfate is used in the reaction, how many formula units of phosphoric acid is needed to completely react?

(1. 28427×1024)

Answers

Sodium sulfate = 1.08 g Amount of sulfuric acid produced = 0.726 g Percent yield of sulfuric acid = 97.3190%1. a) The balanced chemical equation for the reaction is: Na2SO4 + H3PO4 → Na2PO4 + H2SO4

Molar mass of Na2SO4 = 142 g/mol Molar mass of H2SO4 = 98 g/mol Moles of Na2SO4 = 1.08 g / 142 g/mol = 0.0076 mol From the balanced equation, 1 mole of Na2SO4 produces 1 mole of H2SO4Moles of H2SO4 produced = 0.0076 mol

b) Percent yield = (actual yield / theoretical yield) x 100Theoretical yield of H2SO4 = moles of Na2SO4 = 0.0076 mol Actual yield of H2SO4 = 0.726 g / 98 g/mol = 0.0074 mol Percent yield of H2SO4 = (0.0074 mol / 0.0076 mol) x 100 = 97.3190%2.

The balanced chemical equation for the reaction is:Na2SO4 + H3PO4 → Na2PO4 + H2SO4

Moles of Na2SO4 = 3.2

Formula units of H3PO4 needed = Moles of Na2SO4 x 2 x 3 = 3.2 x 2 x 3 = 19.2

Formula units of H3PO4 needed = 1.28427 × 10²⁴.

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At equilibrium, a 1. 0L vessel contains 20. 0 mol of H2, 18. 0 mol of CO2, 12. 0 mol of H2O, and 5. 9 mol of CO at 427oC. What is the value of Keqat this temperature for the following reaction? CO2 (g)+ H2(g) = CO(g)+ H2O

Answers

At a temperature of 427°C, the equilibrium constant (Kₑq) for the given reaction is 0.1092.

The equilibrium constant, Kₑq, represents the ratio of the product of the concentrations of the products, each raised to the power of its coefficient, to the product of the concentrations of the reactants, each raised to the power of its coefficient.

The given reaction is:

CO₂(g) + H₂(g) ⇌ CO(g) + H₂O(g)

Let's write the balanced chemical equation:

CO₂(g) + H₂(g) ⇌ CO(g) + H₂O(g)

Equilibrium concentration of reactants:

[H₂] = 20.0 mol/L

[CO₂] = 18.0 mol/L

Equilibrium concentration of products:

[CO] = 5.9 mol/L

[H₂O] = 12.0 mol/L

Hence, Kₑq is calculated as follows:

Kₑq = ([CO] ⋅ [H₂O])/([CO₂] ⋅ [H₂])

Kₑq = (5.9 ⋅ 12.0)/(20.0 ⋅ 18.0)

Kₑq = 0.1092

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a 8.5-liter sample of a gas has 1.2 mole of the gas. if 0.65 mole of the gas is added, what is the final volume of the gas? temperature and pressure remain constant.
A - 13 L
B- 14 L
C - 18 L
D - 21 L

Answers

A 8.5-liter sample of a gas has 1.2 mole of the gas. If 0.65 mole of the gas is added, the final volume of the gas is approximately 13.098 liters.

The correct answer would be option A.

To solve this problem, we can use the ideal gas law equation, which states:

PV = nRT

Where:

P = Pressure (constant)

V = Volume (unknown)

n = Number of moles

R = Gas constant

T = Temperature (constant)

Since the temperature and pressure are constant in this scenario, we can simplify the ideal gas law equation to:

V = nR/P

Given that the initial volume of the gas is 8.5 liters and the initial number of moles is 1.2 mole, we can calculate the initial volume per mole as follows:

Initial volume per mole (V1) = 8.5 L / 1.2 mol = 7.08 L/mol

Now, we need to find the final volume when 0.65 mole of the gas is added. To calculate the final volume, we can use the same volume per mole ratio:

Final volume (V2) = V1 * (n1 + n2)

Where:

n1 = Initial number of moles

n2 = Additional number of moles

Plugging in the values:

V2 = 7.08 L/mol * (1.2 mol + 0.65 mol)

  = 7.08 L/mol * 1.85 mol

  = 13.098 L

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Calculate the pH of a 0.10 M solution of sodium benzoate (NaC6H5COO) given that the Ka of benzoic acid (C6H5COOH) is 6.50 x 10-5.

Answers

The pH of 0.10 M solution of sodium benzoate (NaC6H5COO) is 4.17.

The problem can be solved by using the formula for calculating the pH of weak acid solution, which is pH = pKa + log ([A⁻]/[HA]).

Benzoic acid (C6H5COOH) is a weak acid and can be represented by the following equation:

C6H5COOH(aq) + H2O(l) ↔ C6H5COO⁻(aq) + H3O⁺(aq)

The Ka of benzoic acid is 6.50 x 10⁻⁵. This means that:

Ka = [C6H5COO⁻][H3O⁺]/[C6H5COOH]

Since the molarity of the sodium benzoate is 0.10 M, we can assume that the molarity of benzoic acid is also 0.10 M. This is because sodium benzoate is a salt formed by the reaction between benzoic acid and sodium hydroxide. Thus, [C6H5COOH] = 0.10 M.

Next, we can calculate the concentration of the benzoate ion. This is because sodium benzoate dissociates into its constituent ions in water: NaC6H5COO(s) → Na⁺(aq) + C6H5COO⁻(aq)

Therefore, [C6H5COO⁻] = 0.10 M.

Using the formula pH = pKa + log ([A⁻]/[HA]), we can now calculate the pH of the solution:

pH = pKa + log ([C6H5COO⁻]/[C6H5COOH])pH = -log(6.50 x 10⁻⁵) + log(0.10/0.10)pH = 4.17

Therefore, the pH of a 0.10 M solution of sodium benzoate (NaC6H5COO) is 4.17.

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Exercise no. 1
Write the dissociation reaction for the following substances
Potasium Hydroxide
Sodium Carbonate
Carbonic Acid
Iron (II) Chloride
Silver Nitrate
Aluminium Hydroxide
Sulfuric Acid
Calcium Bicarbonate
Magnesium Sulfate
Iron (III) Nitrate​

Answers

The dissociation reactions for the given substances are as follows:

1. Potassium Hydroxide: KOH -> K+ + OH-

2. Sodium Carbonate: [tex]Na2CO3[/tex] -> 2Na+ + [tex]CO3^2-[/tex]

3. Carbonic Acid: [tex]H2CO3[/tex] -> H+ + [tex]HCO3-[/tex]

4. Iron (II) Chloride: [tex]FeCl2[/tex] -> [tex]Fe2[/tex]+ + 2Cl-

5. Silver Nitrate: [tex]AgNO3[/tex] -> Ag+ + [tex]NO3[/tex]-

6. Aluminium Hydroxide: Al(OH)3 -> [tex]Al^3[/tex]+ + 3OH-

7. Sulfuric Acid: [tex]H2SO4[/tex] -> 2H+ +[tex]SO4^2-[/tex]

8. Calcium Bicarbonate:[tex]Ca(HCO3)2[/tex]-> [tex]Ca^2[/tex]+ + [tex]2HCO3-[/tex]

9. Magnesium Sulfate: [tex]MgSO4[/tex] -> [tex]Mg^2[/tex]+ + [tex]SO4^2-[/tex]

10. Iron (III) Nitrate:[tex]Fe(NO3)3[/tex]-> [tex]Fe^3[/tex]+ + [tex]3NO3-[/tex]

When certain substances, known as electrolytes, dissolve in water, they dissociate into ions. The dissociation reaction represents the separation of these ions. For example, potassium hydroxide (KOH) dissociates into potassium ions (K+) and hydroxide ions (OH-). Similarly, sodium carbonate ([tex]Na2CO3[/tex]) dissociates into two sodium ions (2Na+) and one carbonate ion ([tex]CO3^2-).[/tex]

Carbonic acid ([tex]H2CO3[/tex]) dissociates into a hydrogen ion (H+) and a bicarbonate ion ([tex]HCO3[/tex]-). Iron (II) chloride ([tex]FeCl2[/tex]) dissociates into an iron ion ([tex]Fe2+[/tex]) and two chloride ions (2Cl-). Silver nitrate ([tex]AgNO3[/tex]) dissociates into a silver ion (Ag+) and a nitrate ion ([tex]NO3[/tex]-).

The dissociation reactions continue for the other substances listed, with the respective cations and anions separating. These dissociation reactions are important in understanding the behavior of these compounds in aqueous solutions and their ability to conduct electricity.

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A 25.0 mL volume of HCl solution of unknown concentration is titrated with a 0.172 M NaOH solution. Neutralization of the HCl solution requires 29.6 mL of the NaOH solution. Calculate the concentration of the HCl solution.

Answers

If the neutralization of the HCl solution requires 29.6 mL of the NaOH solution. The concentration of the HCl solution is 0.203 M.

It is Given that, Volume of HCl solution = 25.0 mL, Volume of NaOH solution = 29.6 mL, Concentration of NaOH solution = 0.172 M

Let the concentration of HCl be x M.

No of moles of NaOH solution = (volume × concentration)

= (29.6 × 0.172)

= 5.0752 × 10^-3 mol.

No of moles of HCl solution = No of moles of NaOH solution

For complete neutralization of HCl by NaOH, the following reaction takes place.

HCl + NaOH → NaCl + H[tex]_2[/tex]O

The stoichiometry of the reaction is 1:1.

So,5.0752 × 10^-3 mol of NaOH neutralizes 5.0752 × 10^-3 mol of HCl.

The concentration of HCl solution can be calculated as follows:

The concentration of HCl solution = (No of moles of HCl) ÷ (Volume of HCl solution in L)

= (5.0752 × 10^-3) ÷ (0.025)

= 0.203 M

Therefore, the concentration of the HCl solution is 0.203 M.

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A 25.0 mL sample of Ba (OH)2 solution was neutralized by 45.3 mL of 0.150 N HCl. What is the Normality of the Ba (OH)2

Answers

The required normality of Ba(OH)2 is 0.1012 N.

A 25.0 mL sample of Ba (OH)2 solution was neutralized by 45.3 mL of 0.150 N HCl. What is the Normality of the Ba (OH)2?The balanced equation for the reaction between Ba(OH)2 and HCl is:Ba(OH)2 + 2HCl → BaCl2 + 2H2OAccording to the reaction equation, we can see that one mole of Ba(OH)2 reacts with two moles of HCl.

The molarity of the HCl is given as 0.150 N, where N is the normality. It can be calculated as shown below:N = M × nwhere M is the molarity of the solution, and n is the number of equivalents.N = 0.150 × 2 = 0.300 NFrom the reaction equation, we know that 2 moles of HCl are required to neutralize 1 mole of Ba(OH)2.25 mL of Ba(OH)2 is neutralized by 45.3 mL of 0.150 N HCl. The amount of Ba(OH)2 can be calculated as follows:Volume of Ba(OH)2 = (45.3 mL / 2) × (25 mL / volume of Ba(OH)2)

volume of Ba(OH)2 = 16.87 mLThe number of moles of Ba(OH)2 in the solution is calculated as follows:n = M × V where M is the molarity and V is the volume.n = M × V = (0.150 N) × (16.87 / 1000 L) = 0.00253 molThe normality of Ba(OH)2 can be calculated using the formula below:N = n / Vwhere n is the number of equivalents and V is the volume.N = n / V = 0.00253 / (25.0 / 1000) = 0.1012 N

Therefore, the normality of Ba(OH)2 is 0.1012 N.

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A metal having a mass 29.94 g at 96.6 oC was placed in a coffee cup calorimeter of negligible heat capacity. The liquid in the calorimeter was 150 mL mercury at 17.7 oC, which specific heat is 0.140 J/g oC. Mercury density is 5.43 g/cm3. If the final temperature of the system was 33.3 oC, what would be the specific heat of that metal

Answers

The specific heat of the metal is approximately -0.953 J/g °C.

To determine the specific heat of the metal, we can use the principle of conservation of energy. The heat gained by the mercury in the calorimeter is equal to the heat lost by the metal.

First, let's calculate the mass of the mercury in the calorimeter. We know the density of mercury is 5.43 g/cm3, and the volume is given as 150 mL:

Mass of mercury = Volume of mercury x Density of mercury

Mass of mercury = 150 mL x 5.43 g/cm3

Mass of mercury = 814.5 g

Next, let's calculate the heat gained by the mercury:

Heat gained by mercury = Mass of mercury x Specific heat of mercury x Change in temperature

Heat gained by mercury = 814.5 g x 0.140 J/g °C x (33.3 oC - 17.7 °C)

Heat gained by mercury = 814.5 g x 0.140 J/g °C x 15.6 °C

Heat gained by mercury = 1809.864 J

According to the principle of conservation of energy, the heat lost by the metal is equal to the heat gained by the mercury:

Heat lost by metal = Heat gained by mercury

Heat lost by metal = 1809.864 J

We know the mass of the metal is 29.94 g. Let's denote the specific heat of the metal as 'C':

Heat lost by metal = Mass of metal x Specific heat of metal x Change in temperature

1809.864 J = 29.94 g x C x (33.3 °C - 96.6 °C)

1809.864 J = 29.94 g x C x (-63.3 °C)

1809.864 J = -1900.802 g oC x C

Solving for C:

C = 1809.864 J / (-1900.802 g °C)

C ≈ -0.953 J/g °C

Therefore, the specific heat of the metal is approximately -0.953 J/g °C.

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on a manganese surface is 35 per cent shorter at 1000 K than at 600 K. What is the activation energy for desorption

Answers

On a manganese surface is 35 per cent shorter at 1000 K than at 600 K. 3564.43 J/mol is the activation energy for desorption.

To determine the activation energy for desorption on a manganese surface, we can use the Arrhenius equation, which relates the rate constant of a reaction to the temperature and activation energy. The Arrhenius equation is given as:

k = A × exp(-Eₐ/RT)

Where:

k = rate constant

A = pre-exponential factor (related to the frequency of molecular collisions)

Eₐ = activation energy

R = gas constant (8.314 J/(mol·K))

T = temperature (in Kelvin)

The length of desorption is 35% shorter at 1000 K compared to 600 K, we can assume that the rate constant at 1000 K is 35% higher than at 600 K. Therefore, we can write the following relationship between the rate constants:

k₂ = 1.35 × k₁

Taking the ratio of the Arrhenius equations for the two temperatures (1000 K and 600 K), we have:

k₂/k₁ = (A × exp(-Eₐ/RT₂)) / (A × exp(-Eₐ/RT₁))

Since the pre-exponential factor (A) cancels out, we can simplify the equation to:

1.35 = exp((Eₐ/R) × (1/T₁ - 1/T₁))

We know the values of T₁ = 600 K and T₂ = 1000 K. Plugging these values into the equation, we can solve for Eₐ:

1.35 = exp((Eₐ/R) × (1/600 - 1/1000))

Taking the natural logarithm (ln) on both sides to eliminate the exponential, we get:

ln(1.35) = (Eₐ/R) × (1/600 - 1/1000)

Solving for Ea:

Eₐ/R = ln(1.35) / (1/600 - 1/1000)

Eₐ = R × (ln(1.35) / (1/600 - 1/1000))

Substituting the value of R = 8.314 J/(mol·K), we can calculate the activation energy:

Eₐ = 8.314 × (ln(1.35) / (1/600 - 1/1000))

Eₐ ≈ 8.314 × (0.3001 / (0.0017 - 0.001))

Eₐ ≈ 8.314 × (0.3001 / 0.0007)

Eₐ ≈ 8.314 × 428.71

Eₐ ≈ 3564.43 J/mol

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While performing a neutralization reaction, Jonna added 28.37 mL of 0.142 M H2SO4 to 43.15 mL of 0.334 M KOH. What concentration of OH-, in M, that is unreacted in the solution after the neutralization is complete

Answers

The balanced equation for neutralization reaction of H2SO4 and KOH is:H2SO4 + 2KOH → K2SO4 + 2H2OWe can use the stoichiometry of the reaction to calculate the number of moles of H2SO4 and KOH.

We have: Volume of H2SO4 solution = 28.37 mL = 0.02837 L Volume of KOH solution = 43.15 mL = 0.04315 L Concentration of H2SO4 solution = 0.142 M Concentration of KOH solution = 0.334 M Number of moles of H2SO4 = Concentration × Volume = 0.142 × 0.02837 = 0.00402854 mol Number of moles of KOH = Concentration × Volume = 0.334 × 0.04315 = 0.0144201 mol From the balanced equation, 2 moles of KOH reacts with 1 mole of H2SO4. Therefore, the number of moles of KOH that reacted is:2 × 0.00402854 = 0.00805708 mol

The remaining number of moles of KOH is the total number of moles of KOH minus the number of moles of KOH that reacted:0.0144201 - 0.00805708 = 0.00636302 mol The volume of the solution is the sum of the volumes of H2SO4 and KOH solutions:0.02837 + 0.04315 = 0.07152 L Therefore, the concentration of OH- that is unreacted is:0.00636302 / 0.07152 = 0.0889 M

Answer: 0.0889 M

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Anthracene, a hydrocarbon obtained from coal, has an empirical formula of C7H5. To find its molecular formula you dissolve 0.500 g in 30.0 g of benzene. The boiling point of the pure benzene is 80.10 °C, whereas the solution has a boiling point of 80.34 °C. What is the molecular formula of anthracene?

Answers

The molecular formula of anthracene is given as: C₂(₇H₅) = C₁₄H₁₀.

Empirical formula of anthracene = C₇H₅

Boiling point of pure benzene = 80.10 °C

Boiling point of solution = 80.34 °C

Weight of anthracene = 0.500 g

Weight of benzene = 30.0 g

To find the molecular formula of anthracene, we need to determine its molecular weight. The elevation of boiling point of a solution depends on the number of solute particles present.

ΔTb = Kb × m

Where:

ΔTb = Elevation of boiling point

Kb = Boiling point elevation constant

m = Molality of solution

Molality of the solution can be calculated as:

m = (Weight of solute in grams / Molar mass of solute) / (Weight of solvent in grams / Molar mass of solvent)

The empirical formula mass of C₇H₅ can be calculated as:

Empirical formula mass = (7 × Atomic mass of carbon) + (5 × Atomic mass of hydrogen)

= (7 × 12.01) + (5 × 1.01)

= 84.08 g/mol

Now, we can find the molecular weight by calculating the ratio of the molecular weight to the empirical formula mass:

Molecular formula = (Molecular weight) / (Empirical formula mass)

To calculate the molecular weight, we need to find the molality of the solution:

m = (0.500 / Molar mass of anthracene) / (30.0 / 78.11)

Where the molar mass of benzene is 78.11 g/mol.

Simplifying the equation, we get:

Molar mass of anthracene = 3 × (0.03413 × 78.11 / 0.500) = 324.32 g/mol

The elevation of boiling point of the solution can be calculated as:

ΔTb = Tb, solution - Tb, pure solvent

= 80.34 - 80.10

= 0.24 °C

Substituting the given values in the first formula, we get:

0.24 = Kb × 3.413

Kb = 0.0702 °C/m

Using Kb and the molality of the solution, we can find the molecular weight of anthracene:

0.0702 = (RT² / 1000 × ΔHfus × m)

T = (80.10 + 80.34) / 2 = 80.22 °C

ΔHfus = 9.90 kJ/mol (from literature)

R = 0.08206 L atm mol⁻¹ K⁻¹

Substituting the values, we get:

324.32 = (0.08206 × 80.22² / 1000 × 9.90 × 3 × 0.03413)

Solving the equation, we find:

Molecular weight of anthracene = 178.22 g/mol

Therefore, the molecular formula of anthracene is given as:

Molecular formula = Molecular weight / Empirical formula mass

= 178.22 / 84.08

= 2.12 ≈ 2

So, the molecular formula is C₂(₇H₅) = C₁₄H₁₀.

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A 0.073 mol sample of formaldehyde vapor, CH2O, was placed in a heated 500 mL vessel and some of it decomposed. The reaction is CH2O(g) H2(g) CO(g) At equilibrium, the CH2O(g) concentration was 0.039 mol L-1. Calculate the value of Kc for this reaction

Answers

The value of Kc (equilibrium constant) for the given reaction will be approximately 0.871 L/mol.

To calculate the value of Kc for the given reaction, we need to use the equilibrium concentrations of the species involved. Given that the CH₂O(g) concentration at equilibrium is 0.039 mol L-1 and the initial CH₂O(g) concentration is 0.073 mol, we can determine the change in concentration;

Change in CH₂O(g) concentration = Initial concentration - Equilibrium concentration

Change in CH₂O(g) concentration = 0.073 mol - 0.039 mol

Change in CH₂O(g) concentration = 0.034 mol

Since the stoichiometric coefficient of CH₂O(g) in the balanced equation is 1, the change in concentration for H₂(g) and CO(g) is also 0.034 mol.

Now, let's consider the balanced equation for the reaction:

CH₂O(g) ⇔ H₂(g) + CO(g)

The equilibrium constant expression, Kc, is given by the ratio of the product concentrations to the reactant concentrations, each raised to their stoichiometric coefficients;

Kc = [H₂(g)] × [CO(g)] / [CH₂O(g)]

Since the change in concentration for each species is 0.034 mol and the volume of the vessel is 500 mL (0.5 L), we can substitute these values into the equation:

Kc = [(0.034 mol / 0.5 L)] × [(0.034 mol / 0.5 L)] / [(0.039 mol / 0.5 L)]

Kc = (0.068 mol² / L²) / (0.078 mol / L)

Kc = 0.871 L / mol

Therefore, the value of Kc is 0.871 L/mol.

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What is the symbol for the element with an electron configuration of 1s^22s^22p^63s^23p^51s 2 2s 2 2p 6 3s 2 3p 5 1, s, squared, 2, s, squared, 2, p, start superscript, 6, end superscript, 3, s, squared, 3, p, start superscript, 5, end superscript

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The element with an electron configuration of 1s²2s²2p⁶3s²3p⁵ has the symbol Br. Bromine (Br) is the element that has the given electron configuration.

Bromine is a chemical element that is known by the symbol Br and has the atomic number 35. The chemical symbol for bromine is derived from the Greek word "bromos," which means "stench," as a result of its highly unpleasant odor. The element bromine is a dark red-brown liquid that evaporates quickly at room temperature, forming a red-brown vapor. It is highly corrosive and reactive and is present as a diatomic molecule Br2 under ordinary conditions.

An electron configuration refers to the manner in which electrons are organized inside an atom. The position of electrons inside an atom is crucial to its physical and chemical characteristics. The electron configuration of an atom can be represented using the format: 1s²2s²2p⁶3s²3p⁵. The electron configuration of an atom influences its chemical characteristics. The position of electrons inside an atom determines how reactive it is, as well as how it interacts with other atoms. The electron configuration provides information about the number of electrons in each energy level and helps to describe how an element will react.

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Muonium is a transient atom with a proton nucleus and a negative muon. The muon is an elementary particle with a charge the same as that of an electron (-e) and a mass 206.77 times greater than that of the electron. Predict the wavenumbers of the first three lines of the Lyman series of muonium.


Required:

What is the ionization energy from the ground state of muonium?

Answers

The ionization energy from the ground state of muonium is approximately 13.6 eV.

The ionization energy of an atom is the energy required to remove an electron from its ground state, resulting in an ion.

The energy levels of muonium can be approximated using the same principles as the hydrogen atom since it consists of a proton and a negative muon, which behaves similarly to an electron.

The ionization energy of muonium can be calculated using the Rydberg formula, which relates the ionization energy to the wavenumber (reciprocal of the wavelength) of the photon absorbed or emitted during the transition. For the Lyman series, the transitions occur from higher energy levels to the ground state.

The formula for the wavenumber (ν) of the Lyman series lines is given by:

1/ν = R * (1/n_final² - 1/n_initial²)

where R is the Rydberg constant (approximately 1.097 × 10⁷ m⁻¹), n_final is the final energy level, and n_initial is the initial energy level.

For the first three lines of the Lyman series, we have:

Line 1: n_initial = 2,

n_final = 1

Line 2: n_initial = 3,

n_final = 1

Line 3: n_initial = 4,

n_final = 1

Using the formula, we can calculate the wavenumbers for these lines:

For Line 1:

1/ν = R * (1/1² - 1/2²)

1/ν = R * (1 - 1/4)

1/ν = R * (3/4)

ν = 4/3R

ν ≈ 3.064 × 10⁶m⁻¹

For Line 2:

1/ν = R * (1/1² - 1/3²)

1/ν = R * (1 - 1/9)

1/ν = R * (8/9)

ν = 9/8R

ν ≈ 1.361 × 10⁶m⁻¹

For Line 3:

1/ν = R * (1/1² - 1/4²)

1/ν = R * (1 - 1/16)

1/ν = R * (15/16)

ν = 16/15R

ν≈ 9.258 × 10⁵m⁻¹

To convert the wavenumbers to electron volts (eV), we can use the relationship:

Energy (eV) = h * c * ν

where h is the Planck's constant (approximately 4.136 × 10^(-15) eV*s) and c is the speed of light (approximately 2.998 × 10^8 m/s).

Calculating the ionization energy for each line:

For Line 1:

Energy = 4.136 × 10¹⁵ eV*s * 2.998 ×10⁸ m/s * 3.064 × 10⁶m⁻¹

Energy≈ 12.59 eV

For Line 2:

Energy = 4.136 ×  10¹⁵  eV*s * 2.998 × 10⁸ m/s * 1.361 × 10⁶m⁻¹

Energy ≈ 13.56 eV

For Line 3:

Energy = 4.136 ×  10¹⁵  eV*s * 2.998 × 10⁸ m/s * 9.258 × 10⁵m⁻¹

Energy ≈ 13.60 eV

The ionization energy from the ground state of muonium, calculated from the first three lines of the Lyman series, is approximately 13.6 eV.

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If 273.1 mL of SO2 is allowed to react with 155.2 mL of O2 (both measured at 317 K and 46.8 mmHg ), what is the limiting reactant

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If 273.1 mL of SO₂ is allowed to react with 155.2 mL of O₂ (both measured at 317 K and 46.8 mmHg ). Then, the limiting reactant is O₂.

To determine the limiting reactant, we need to compare the number of moles of each reactant and see which one is present in the lower amount.

First, we need to convert the volumes of the gases to the number of moles using the ideal gas law equation;

PV = nRT

Where P will be the pressure, V will be the volume, n will be the number of moles, R will be the gas constant, and T will be the temperature.

Given;

Volume of SO₂ (V₁) = 273.1 mL = 0.2731 L

Volume of O₂ (V₂) = 155.2 mL = 0.1552 L

Pressure (P) = 46.8 mmHg

Temperature (T) = 317 K

Now, we will calculate the number  of moles for each gas;

n₁ =(P × V₁) / (R × T)

n₂ =(P × V₂) / (R × T)

Assuming the gas constant (R) is 0.0821 L·atm/(mol·K), we can substitute the given values;

n₁ = (46.8 mmHg × 0.2731 L) / (0.0821 L·atm/(mol·K) × 317 K)

n₂ = (46.8 mmHg × 0.1552 L) / (0.0821 L·atm/(mol·K) × 317 K)

Calculating these values gives;

n₁ ≈ 0.0046 mol

n₂ ≈ 0.0026 mol

From these calculations, we see that SO₂ has a larger number of moles (0.0046 mol) compared to O2 (0.0026 mol). Therefore, SO₂ is the excess reactant, and O₂ is the limiting reactant.

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What are the units for measuring the componets stated in Charles Law?

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The units for measuring the components in Charles's Law are temperature and volume.

Charles's Law states that the volume of a gas is directly proportional to its temperature, provided that the pressure and amount of gas remain constant. In this context, temperature refers to the average kinetic energy of the gas particles, and volume refers to the physical space occupied by the gas.

Temperature can be measured using different scales, such as degrees Celsius (°C) or Kelvin (K). The Celsius scale is commonly used in everyday measurements, while the Kelvin scale is often used in scientific calculations. The Kelvin scale is an absolute temperature scale where 0 K represents absolute zero, the point at which all molecular motion ceases.

Volume can be measured in various units, including liters (L) or cubic centimeters (cm³). The liter is a commonly used unit for measuring the volume of gases, especially in laboratory experiments. The cubic centimeter (cm³) is equivalent to one milliliter (mL) and is also used to measure gas volumes, particularly in scientific research.

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________ screens use organic compounds between the glass layers that light up when given an electrical charge, which means they require no backlight at all.

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OLED screens use organic compounds between the glass layers that light up when given an electrical charge, which means they require no backlight at all.

OLED stands for Organic Light-Emitting Diode. OLED screens are a type of display technology that utilizes organic compounds to emit light when an electric current is applied. Unlike traditional LCD screens, OLED screens do not require a separate backlight as each pixel emits its own light.

This allows for greater control over individual pixels, resulting in deeper blacks, higher contrast ratios, and wider viewing angles.

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You measured an absorbance of 0.250 for an unknown glucose solution and 0.350 for a standard 5 mg/dL glucose solution. Calculate the concentration of the unknown glucose solution. Use 3 decimal places

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An absorbance of 0.250 for an unknown glucose solution and 0.350 for a standard 5 mg/dL glucose solution, the concentration of the unknown glucose solution is 3.571 × 10⁻⁶ mol/L.

The Beer-Lambert law describes the relationship between absorbance, molar absorptivity, concentration, and path length. A = εbc, where A is absorbance, ε is molar absorptivity, b is path length, and c is concentration. This equation is used to determine the concentration of an unknown substance by comparing its absorbance to that of a known standard at the same wavelength.

The concentration of the unknown glucose solution can be calculated as follows: Step 1: Calculate the molar absorptivity of glucose at the given wavelength (assumed to be the same for both solutions).ε = A/bcε = (0.350)/(5 mg/dL × 1 dL/1000 mL × 1/1.0 cm)ε = 70 L/(mol·cm)Step 2: Use the molar absorptivity value to determine the concentration of the unknown glucose solution.c = A/εbc = (0.250)/(70 L/(mol·cm) × 1 cm × 1/1000 L) = 3.571 × 10⁻⁶ mol/LThe concentration of the unknown glucose solution is 3.571 × 10⁻⁶ mol/L. Answer: 3.571 x 10⁻⁶ mol/L

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write an equilibrium equation for the phase equilibrium that occurs in a sealed bottle of bromine at 25 C

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The equilibrium equation for the phase equilibrium that occurs in a sealed bottle of bromine at 25 °C can be represented as follows:

[tex]\[ \text{Br}_2(g) \rightleftharpoons \text{Br}_2(l) \][/tex]

In this equation, Br₂(g) represents gaseous bromine, and Br₂(l) represents liquid bromine. The double arrows indicate that the reaction is reversible and that both the forward and reverse reactions can occur.

At equilibrium, the rate of the forward reaction (vaporization of liquid bromine) is equal to the rate of the reverse reaction (condensation of gaseous bromine). This equilibrium is established when the vapor pressure of the liquid bromine is equal to the partial pressure of the gaseous bromine.

The temperature of 25 °C is important in determining the equilibrium because it influences the vapor pressure of the liquid bromine.

At this temperature, the equilibrium is established between the gas phase and the liquid phase of bromine inside the sealed bottle.

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A freshly prepared sample of a certain radioactive isotope has an activity of 10000 Bq. After an elapsed time of 4 hours, its activity is 7000 Bq. How many atoms of the isotope were contained in the freshly prepared sample

Answers

The number of atoms of the radioactive isotope in the freshly prepared sample is approximately 1.85 x [tex]10^1^8[/tex] atoms.

How many atoms were present in the freshly prepared sample of the radioactive isotope?

To determine the number of atoms in the sample, we can use the concept of radioactive decay and the relationship between activity, time, and the decay constant. The activity of a radioactive substance decreases over time due to the decay of its atoms.

By comparing the initial activity (10000 Bq) with the activity after 4 hours (7000 Bq), we can calculate the fraction of remaining atoms. Assuming exponential decay, we can use the decay constant to find the number of atoms present in the sample.

Using the equation for radioactive decay, we find that the number of atoms in the freshly prepared sample is approximately 1.85 x [tex]10^1^8[/tex] atoms.

Radioactive decay is a fundamental concept in nuclear physics and plays a crucial role in various applications, including radiometric dating and medical imaging. Understanding the relationship between activity, time, and the number of atoms allows scientists to study the behavior and properties of radioactive materials.

The decay constant, specific to each radioactive isotope, determines the rate of decay and provides valuable information about the stability and half-life of the isotope. Accurate measurement and calculation of radioactive decay are essential in both scientific research and practical applications.

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Calculate the percent ionization of a 0.593 M solution of acetylsalicylic acid (aspirin), HC9H7O4. % Ionization

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Acetylsalicylic acid (aspirin), HC9H7O4, in a 0.593 M solution has a percent ionization of 0.784 percent.

In a solution, ionization is the process of producing ions. A chemical substance that splits into electrically charged particles, ions, when dissolved in water is said to undergo ionization. The ionization constant (Ka) is a measure of the tendency of a weak acid to ionize, which is calculated by multiplying the molar concentration of the ionized acid by the molar concentration of the hydrogen ion to get the concentration of the undissociated acid divided by the concentration of the dissociated acid squared. In addition, the equation for calculating percent ionization is as follows: % ionization = (ionized concentration/initial concentration) × 100 percent. Calculation Acetyl salicylic acid is a weak acid that partially ionizes in aqueous solution, producing H+ ions. The following equation represents the ionization of aspirin in water: HC9H7O4 + H2O → H3O+ + C9H7O4¯ Initially, the concentration of the undissociated acid is equal to the initial concentration. The ionized concentration is determined by the ionization constant (Ka) and the initial concentration. For weak acids such as acetylsalicylic acid, the value of Ka is typically small. So, at equilibrium, the concentration of ionized acid is also quite small.

To find % ionization, we use the equation: % ionization = (ionized concentration/initial concentration) × 100 percent From the equation:HC9H7O4 + H2O → H3O+ + C9H7O4¯Initial Concentration: 0.593 M Concentration of H3O+ ion (ionized concentration): x Concentration of C9H7O4¯ ion (ionized concentration): x The amount of HC9H7O4 that ionizes is equal to the amount of H3O+ ions formed, which is equal to the amount of C9H7O4¯ ions formed. Thus, we can consider the equilibrium concentrations to be 0.593 - x for HC9H7O4, x for H3O+, and x for C9H7O4¯.Ka = [H3O+] [C9H7O4¯]/[HC9H7O4] Ka = (x)²/(0.593 - x) Using the quadratic formula, we can solve for x, the concentration of ionized acid. This will be approximately equal to the concentration of H3O+.Ka = (x)²/(0.593 - x)0.784 x 10¯5 = (x)²/(0.593 - x)x = 0.000053 M Therefore, ionized concentration = 0.000053 M So, % ionization = (ionized concentration/initial concentration) × 100% = (0.000053/0.593) × 100%= 0.784 %Therefore, the percent ionization of a 0.593 M solution of acetylsalicylic acid (aspirin), HC9H7O4, is 0.784 percent.

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A student places a dry seahorse in a glass of water. after 30 minutes, the seahorse has grown to be double in size.
30
minutes

the student claims that based on growth, the seahorse is a living organism. which test could the student use to verify if the seahorse is a living organism?
o put the seahorse in water with a different temperature, and see if the seahorse changes color.
remove the seahorse from the water, and see if the seahorse returns to its original size.
add food to the water, and see if the seahorse eats the food.
shake the glass of water, and see if the seahorse moves.

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The test the student could use to verify if the seahorse is a living organism is to add food to the water and observe if the seahorse eats the food.

Eating is a characteristic behavior of living organisms, as they need to consume energy and nutrients to sustain their biological processes. By offering food to the seahorse and monitoring its response, the student can determine if it actively engages in feeding behavior. If the seahorse consumes the food, it would indicate that it is a living organism capable of obtaining energy from external sources. The other options mentioned in the question are not suitable tests for verifying if the seahorse is a living organism. Changing the water temperature and observing color changes do not necessarily indicate if an organism is alive. Removing the seahorse from water and observing its size change does not provide information about its life processes. Shaking the glass of water may cause temporary movement, but it does not necessarily demonstrate the seahorse’s ability to respond to stimuli or exhibit self-directed movement. In summary, the most appropriate test to determine if the seahorse is a living organism would be to observe its response to the presence of food, as feeding behavior is a characteristic of living organisms.

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An unknown sample and brought up to 100.0 mL volume. From that solution, 10.00 mL is removed and added to a 50.00 mL volumetric flask and the contents of the flask. This second solution, the one in the 50.00 mL volumetric flask gives a response for compound X of 0.3148. Another 10.00 mL another 50.00 mL volumetric flask. A standard solution of compound X has a concentration of 5.75 ppm and 10.00 mL of that standard solution is added to the same 50.00 mL flask. This flask is diluted to volume with 0.01 M HCl. This second flask has a response for Compound X of 0.6979. Find the %w/w (ie g/g x 100%) of compound X in the original unknown sample.

Answers

The %w/w (ie g/g x 100%) of compound X in the original unknown sample is 0.6909%.

To calculate the %w/w of compound X in the original unknown sample, we need to follow the given procedure. We are given:

Volume of original unknown sample = 100 mLVolume of aliquot taken = 10.00 mLResponse for compound X of the second solution in 50.00 mL volumetric flask = 0.3148Response for compound X of the second flask in 50.00 mL volumetric flask = 0.6979Concentration of standard solution of compound X = 5.75 ppm

Step 1: Calculation of the concentration of compound X in the second solution

From the formula of dilution, C₁V₁ = C₂V₂ where, C₁ is  concentration of the original solution, V₁ is volume of original solution, C₂ is concentration of second solution, and V₂ is volume of the solution obtained after dilution.

Using the above formula C₁ × V₁ = C₂ × V₂ concentration of compound X in the second solution (C₂) can be calculated as C₂ = C₁ × V₁ / V₂.

We know that V₁ = 10.00 mL and V₂ = 50.00 mL and the response for compound X of the second solution in 50.00 mL volumetric flask is 0.3148. Putting the values in the above formula,

C₂ = C₁ × V₁ / V₂

= 0.3148 ppm

Step 2: Calculation of the concentration of compound X in the second flask

Standard solution of compound X has a concentration of 5.75 ppm, 10.00 mL of that standard solution is added to the same 50.00 mL flask. Thus, the total volume of the solution becomes 10.00 mL + 50.00 mL = 60.00 mL.

To calculate the concentration of compound X in the second flask, we can use the same formula that we used to calculate the concentration of compound X in the second solution.

C₂ = C₁ × V₁ / V₂ where C₂ is concentration of compound X in the second flask, C₁ is concentration of the second solution, V₁ is volume of solution taken from the second solution, and V₂ is volume of the second flask.

We know that C₂ = 0.6979 ppm, C₁ = 0.3148 ppm, V₁ = 10.00 mL, V₂ = 60.00 mL. By putting the values in the above formula, we get,

C₂ = C₁ × V₁ / V₂

= 0.3148 × 10 / 60

= 0.0525 ppm

Step 3: Calculation of %w/w of compound X in the original unknown sample

Concentration of compound X in the original unknown sample is C₃. Let's use the formula that we used to calculate C₂,

C₁ × V₁ = C₂ × V₂

C₃ × 100 = C₂ × (100 / 10) / 100.00 / 100

Where, C₃ is concentration of compound X in the original unknown sample, C₂ is 0.0525 ppm, V₁ = 10.00 mL, V₂ = 50.00 mL. By putting the values in the above formula, we get,

C₃ = (C₂ × V₂ × 100) / V1 / 100

= (0.0525 × 50.00 × 100) / 10.00 / 100

= 0.2625 ppm

Now, let's calculate the %w/w of compound X in the original unknown sample. We are  given:

Weight of the original unknown sample = Volume of the original unknown sample × Density of the original unknown sample

= 100 mL × 1.00 g/mL

= 100 g

Let's assume the mass of compound X in the original unknown sample is m g. Hence, the mass of the solvent (H₂O) in the original unknown sample is (100 - m) g.

Concentration of compound X in the original unknown sample = mass of compound X / mass of the original unknown sample

= (m / 100) / (100 - m) g / g

By using the formula,

Concentration (ppm) = mass (g) / volume (L) × 10⁶

= (m / 100) / (100 - m) g / g × 10⁶ / 100 mL / L

= m / (100 - m) × 10⁴ ppm

Given, concentration of compound X in the original unknown sample = 0.2625 ppm. By putting the above value in the above formula, we get,

0.2625 = m / (100 - m) × 10⁴

By solving the above equation, we get, m = 0.6909 g. Therefore, the mass of compound X in the original unknown sample is 0.6909 g. And the mass of the original unknown sample is 100 g. Therefore, the %w/w of compound X in the original unknown sample is,

%w/w = mass of compound X in the original unknown sample / mass of the original unknown sample × 100

= 0.6909 / 100 × 100%

= 0.6909% (Approx)

Hence, the required %w/w of compound X in the original unknown sample is approximately 0.6909%.

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Consider the chemical equations shown here. 2Na(s) Cl2(g) → 2NaCl(s) 4Na(s) O2(g) → 2Na2O(s) What is the overall equation for the reaction that produces NaCl and O2 from Na2O and Cl2? Upper N a subscript 2 upper O (s) plus upper C l subscript 2 (g) right arrow upper N a upper C l (s) plus upper O subscript 2 (g). 2 upper N a subscript 2 upper O (s) plus upper C l subscript 2 (g) right arrow 2 upper N a upper C l (s) plus upper O subscript 2 (g). 2Upper N a subscript 2 upper O (s) plus 2 upper C l subscript 2 (g) right arrow 4 upper N a upper C l (s) plus upper O subscript 2 (g).

Answers

The given chemical equations are:2Na(s) + Cl2(g) → 2NaCl(s)4Na(s) + O2(g) → 2Na2O(s). To derive the overall equation, we need to add the two equations such that the reactants and products get balanced. Here, the Na atom is present on the reactant side of both equations and the Cl atom is present on the product side in the first equation and the reactant side in the second equation.

Hence, we can add the two equations as follows:2Na(s) + Cl2(g) + 4Na(s) + O2(g) → 2NaCl(s) + 2Na2O(s).

Now, we need to simplify the equation by cancelling out the common terms.

Here, Na and Cl atoms are balanced, but there are two Na2O molecules on the product side, which can be simplified to one by dividing each side by 2.

This gives the overall equation as:2Na2O(s) + 2Cl2(g) → 4NaCl(s) + O2(g).

Therefore, the correct option is:2Na2O(s) + 2Cl2(g) → 4NaCl(s) + O2(g).

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Combustion analysis of an unknown compound containing only carbon and hydrogen produces 8.80 g CO2 and 1.44 g H2O. What is the empirical formula of the unknown

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The empirical formula of the unknown compound is [tex]C_{5}H_{2}.[/tex].

To determine the empirical formula of the unknown compound, we need to find the mole ratios of carbon and hydrogen in the compound based on the given masses of [tex]CO_{2}[/tex] and [tex]H_{2}O[/tex] produced.

1. Calculate the moles of  CO₂:

  Moles of  CO₂ = mass of  CO₂ / molar mass of  CO₂

              = 8.80 g / 44.01 g/mol (molar mass of CO₂)

              ≈ 0.1995 mol

2. Calculate the moles of [tex]H_{2}O[/tex]:

  Moles of [tex]H_{2}O[/tex] = mass of [tex]H_{2}O[/tex] / molar mass of [tex]H_{2}O[/tex]

              = 1.44 g / 18.02 g/mol (molar mass of H₂O)

              ≈ 0.0799 mol

3. Determine the mole ratio between carbon and hydrogen:

  Carbon-to-hydrogen mole ratio = moles of  CO₂ / moles of [tex]H_{2}O[/tex]

                               = 0.1995 mol / 0.0799 mol

                               ≈ 2.496

The mole ratio between carbon and hydrogen is approximately 2.496. To find the simplest whole-number ratio, we can multiply both values by a common factor to obtain whole numbers. In this case, we can multiply by 2 to get a whole number ratio of 5:2.

Therefore, the empirical formula of the unknown compound is C₅H₂.

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for a given number of moles of solute, why do ionic substances have a larger effect on the freezing and boiling points of solvents than do non-ionic or moelcular substances

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Ionic substances have a larger effect on the freezing and boiling points of solvents than non-ionic or molecular substances for a given number of moles of solute due to their dissociation in water.

When ionic substances are added to solvents, they undergo dissociation into cations and anions, which can subsequently interact with the solvent molecules through ion-dipole interactions. Ionic substances cause the solvent's freezing point to decrease and boiling point to increase because these interactions are strong and require more energy to separate the ions and solvent molecules.

In comparison to the number of ions present, fewer non-ionic or molecular substances are able to interact with solvent molecules due to their lack of charge. They dissolve in water by forming hydrogen bonds, but they do not dissociate.

This is why ionic substances have a larger impact on the freezing and boiling points of solvents than non-ionic or molecular substances, even for a given number of moles of solute.

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You placed a dialysis bag containing 2% starch solution in a beaker containing pure water. After 30 minutes, when you added Lugol's iodine solution in the beaker, what would you predict immediately

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The water containing 2% starch solution will not change color immediately when lugol's iodine is added. A dialysis bag is a membrane that is semipermeable and holds the fluids that the kidneys normally remove. They are also used in the experiments.

A solution made of potassium iodide and iodine is known as lugol's iodine. The properties can be used as a reagent and an antiseptic and could be used to diagnose cancer. The iodine in Lugol's solution binds to glycogen's alpha-1,4 glucans, which are polysaccharides. This solution takes time to develop blue color when added to the 2% starch solution.

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