researchers have found that fetal heart rate ___ when it hears a familiar story, suggesting

A pure substance will preferably emerge as a network of large crystals after recrystallization. If not this then, it may be appropriate to reheat the flask and allow the contents to cool more slowly. Thus, a is the correct option.

The procedure used to purify an impure compound in a solvent is called recrystallization. The concept used here is that the solubility of most solids increases with an increase in temperature.

Recrystallization is also known as a method of fractional crystallization. Following recrystallization, a pure substance will preferably seem like a network of large crystals. It may be useful to reheat the flask and allow the contents to cool further slowly if this is not the case.

To learn more about recrystallization,

brainly.com/question/28588509

#SPJ4

In water, when CH3COCH3 dissolves, there is just one particle present in the solution.

Acetone's chemical formula is either CH3COCH3 or C3H6O. With only three molecules of carbon, six hydrogen atoms, but one oxygen atom, it is the most basic ketone. Two methyl groups are joined to the center carbon atom, or the sp2 hybridized carbon atom, in the acetone molecule.

A carboxylate ester having the formula CH3COOCH3, methyl acetate is sometimes referred to as MeOAc, acetic anhydride methyl ester, or methyl ethanoate. It is a combustible liquid with a distinctively calming aroma resembling various glues & nail polish removers.

To know more about CH3COCH3 visit:

https://brainly.com/question/26936825

#SPJ4

1-(1-phenylcyclohexyl) piperidine hydrochloride (PCP) was patented as Sernyl and first tested as a dissociative anesthetic.

The main way that 1-(1-Phenylcyclohexyl)piperidine hydrochloride (PCP) affects the central nervous system is either by stimulating it or by depressing it. The signs and symptoms can differ greatly depending on the animal species and dosage. Rats and mice exhibit hyperactivity more conspicuously, and at all dose levels, these animals can also exhibit some signs of central depression, which include a loss of limb muscle coordination.

At low doses, PCP has a calming or quieting effect on pigeons, guinea pigs, hamsters, rabbits, cats, dogs, and monkeys, while at higher doses, it causes a cataleptoid reaction to general anesthesia. Pigeons, guinea pigs, dogs, and monkeys that receive PCP at dosages greater than those used for general anesthesia experience convulsive seizures. Contrarily, convulsion or exhilaration are not immediately apparent.

Learn more about PCP:

https://brainly.com/question/28304545

#SPJ4

For an enzyme that follows Michaelis-Menten kinetics, Km (the Michaelis constant) is equal to the substrate concentration at which the reaction rate is half of its maximum value.

Mathematically, Km is defined as the substrate concentration at which the initial reaction velocity is equal to one-half of the maximum reaction velocity (Vmax) of the enzyme.

In other words, Km is a measure of the affinity of the enzyme for its substrate. Enzymes with a lower Km have a higher affinity for their substrate, meaning that they can effectively bind and catalyze the reaction at lower substrate concentrations.

On the other hand, enzymes with a higher Km have a lower affinity for their substrate and require higher substrate concentrations to achieve the same reaction rate.

To know more about Michaelis-Menten kinetics here

https://brainly.com/question/29361713

#SPJ4

The curved arrow can be used to show the movement of electrons.

The question is incomplete hence I will talk about the use of the curved arrow notation.

To use the curved arrow notation, Identify the bonds that will be broken and the bonds that will be formed in each step of the reaction. You can use the standard notation to show the movement of electrons, where a single-headed arrow (->) represents the movement of a single electron, and a double-headed arrow (<->) represents the movement of two electrons.

The total number of electrons involved in the reaction is conserved, and that the formal charges of the atoms remain the same before and after each step.

Learn more about reaction mechanism:https://brainly.com/question/26690612

#SPJ1

The mass of helium in the tire is 0.0452 g. To calculate the mass of helium in the tire, we need to use the ideal gas law, which relates the pressure, volume, and temperature of a gas to its number of moles and therefore its mass: PV = nRT

To calculate the mass of helium in the tire, we need to use the ideal gas law, which relates the pressure, volume, and temperature of a gas to its number of moles and therefore its mass:

PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the universal gas constant, and T is the temperature.

We know the pressure, volume, and temperature of the helium in the tire, so we can solve for the number of moles of helium:

n = PV/RT

where R = 0.08206 L atm/K mol is the universal gas constant.

Substituting the values given:

n = (7.80 atm) x (0.365 L) / [(0.08206 L atm/K mol) x (25°C + 273.15)]

n = 0.0113 mol

Finally, we can calculate the mass of the helium using the molar mass of helium, which is 4.003 g/mol:

mass = n x molar mass

mass = 0.0113 mol x 4.003 g/mol

mass = 0.0452 g

Therefore, the mass of helium in the tire is 0.0452 g.

Learn more about ideal gas here:

https://brainly.com/question/28257995

#SPJ4

Exothermic processes are those in which heat is evacuated from a substance, as in freezing or condensation.

The correct answer is D

Endothermic chemical reactions are those in which all reactants take in heat that the environment provides to create products. An fast pyrolysis is one in which heat or light are released as forms of energy. Energy from the environment is taken up by the reaction.

An exothermic process in chemistry involves the release off heat. Since heat is released during candle burning, the process is exothermic. Exothermic is a useful scientific adjective to use when describing reactions that release energy, typically in the form of heat.

To know more about exothermic visit:

https://brainly.com/question/4345448

#SPJ4

The bromocresol green indicator will change colors to detect the endpoint of the titration of the borate ion with HCl. Option C is correct.

The endpoint of the titration of the borate ion with HCl can be detected using an indicator.

The borate ion is an anion that contains boron and oxygen atoms. It has a chemical formula of BO₃⁻³, which means it has three negative charges.

One suitable indicator for this titration is phenolphthalein, which is colorless in acidic solutions and appears pink in basic solutions. At the endpoint, when all the borate ions have reacted with the HCl, the solution will become acidic and the phenolphthalein indicator will change color from pink to colorless.

Hence, C. The bromocresol green indicator will change colors is the correct option.

To know more about borate ion here

https://brainly.com/question/27471884

#SPJ4

option (c) 1.424×10^24 oxygen atoms.To determine the number of oxygen atoms in 52.06 g of carbon dioxide, we first need to calculate the number of moles of carbon dioxide present in the given sample.

The molar mass of carbon dioxide is 44.01 g/mol, which means that 1 mole of carbon dioxide contains 6.022×10^23 molecules. Therefore, the number of moles of carbon dioxide present in 52.06 g of the compound can be calculated as follows:

Number of moles = Mass/Molar mass = 52.06 g / 44.01 g/mol = 1.182 mol

Each molecule of carbon dioxide contains one carbon atom and two oxygen atoms. Thus, the total number of oxygen atoms in the sample can be calculated by multiplying the number of moles of carbon dioxide by the number of oxygen atoms per molecule and Avogadro's number (6.022×10^23):

Number of oxygen atoms = 2 × Number of moles × Avogadro's number

= 2 × 1.182 mol × 6.022×10^23

= 1.424×10^24

Therefore, the correct answer is option (c) 1.424×10^24 oxygen atoms.

Find  out more about oxygen

brainly.com/question/30812745

#SPJ4

Only a Bronsted-Lowry base A classification is given to H2SO4 (aq).

A minor rise in reaction temperature will result in a significant increase in the size of the reaction-rate constant, according to the equation, which is frequently expressed as an exponential function, k = Aexp(E/RT).

Inferred from the exponential part in the Following formula is that as the activation energy diminishes, a reaction's rate constant grows exponentially. The rate of a reaction increases exponentially because the rate is directly equivalent to the speed constant of a reaction.

To know more about Arrhenius visit:

https://brainly.com/question/516295

#SPJ1

As the concentration of ferrous iron decreases, your sample absorbs less light, therefore more light reaches the detector.

When a sample containing ferrous iron is exposed to light at a specific wavelength, some of the light is absorbed by the ferrous iron molecules in the sample. This results in a decrease in the intensity of the light that reaches the detector, which is measured as the absorbance of the sample.

The amount of light absorbed by the ferrous iron molecules is directly proportional to their concentration in the sample. Therefore, if the concentration of ferrous iron in the sample decreases, there are fewer molecules to absorb the light, and more light reaches the detector. This results in a lower absorbance reading for the sample.

Learn more about concentration of ferrous iron here: https://brainly.com/question/30692916

#SPJ1

Taking into account the reaction stoichiometry, 124 grams of Na₂O are required to produce 160 grams of NaOH.

In first place, the balanced reaction is:

Na₂O + H₂O → 2 NaOH

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

The following rule of three can be applied: if by reaction stoichiometry 80 grams of NaOH are produced by 62 grams of Na₂O, 160 grams of NaOH are produced by how much mass of Na₂O?

mass of Na₂O= (160 grams of NaOH× 62 grams of Na₂O)÷ 80 grams of NaOH

mass of Na₂O= 124 grams

Finally, 124 grams of Na₂O are required.

Learn more about the reaction stoichiometry:

brainly.com/question/24741074

#SPJ1

The main idea of the quantum mechanical model is that it describes particles, such as electrons, as having both wave-like and particle-like properties.

The quantum mechanical model is a modern and more accurate description of the behavior of atoms and subatomic particles than the classical mechanical model.

According to the quantum mechanical model, electrons in atoms are described by mathematical functions called wave functions, or orbitals, which give the probability of finding the electron at any given location in space.

The quantum mechanical model also explains the electronic structure of atoms, including the number and distribution of electrons in their orbitals, and how electrons are arranged in energy levels and sublevels.

To know more about quantum mechanical model here

https://brainly.com/question/29597957

#SPJ4

The molar mass of sulfuric acid (H₂SO₄) is approximately 98.08 g/mol.

Look up the atomic masses of each element in the formula:

Hydrogen (H): 1.01 g/mol

Sulfur (S): 32.06 g/mol

Oxygen (O): 16.00 g/mol

Count the number of atoms of each element in one molecule of sulfuric acid:

2 atoms of hydrogen (H)

1 atom of sulfur (S)

4 atoms of oxygen (O)

Multiply the atomic mass of each element by the number of atoms of that element, then add the results together:

(2 x 1.01 g/mol) + (1 x 32.06 g/mol) + (4 x 16.00 g/mol) = 98.08 g/mol

To know more about the molar mass, here

brainly.com/question/27907091

#SPJ4

--The complete question is, What is the molar mass of H₂SO₄?--

Answer:

Ernest Rutherford used alpha particles in his famous gold foil experiment to test the Plum Pudding Model of atomic structure because they have a high energy and a large mass.

The Plum Pudding Model proposed by J.J. Thomson suggested that atoms consisted of a uniform, positively charged sphere with negatively charged electrons embedded within it, much like plums in a pudding. However, Rutherford's observations of the scattering of alpha particles as they passed through the gold foil showed that the Plum Pudding Model was incorrect.

When Rutherford directed a beam of alpha particles at a thin sheet of gold foil, he expected the alpha particles to pass straight through or be slightly deflected by the electrons in the gold atoms. However, he observed that a small fraction of the alpha particles were deflected at large angles or even bounced back in the direction from which they came. This could only be explained if the mass of the atom was concentrated in a small, positively charged nucleus at the center, surrounded by mostly empty space.

The reason that Rutherford used alpha particles in his experiment was because their high energy and large mass allowed them to penetrate the atoms of the gold foil and interact with the positively charged nucleus, revealing its presence and disproving the Plum Pudding Model.

Explanation:

Answer:

Rutherfords gold foil experiment involved sending positively charged alpha particles through a thin sheet of gold foil and defecting if there was any deflection of the particles. He found that most passed straight through yet some particles showed some deflection. This result contradicts the plum-pudding model of the atom because the plum pudding model does not explain the deflection of alpha particles.

Explanation:

Alpha particles are positive, so they might be repelled by any areas of positive charge inside the gold atoms. Assuming a plum pudding model of the atom, Rutherford predicted that the areas of positive charge in the gold atoms would deflect, or bend, the path of all the alpha particles as they passed through.

The step we should take to remedy the situation is that we should scratch the inside of the test tube by glass rod.

Generally the dissolution process is defined as the process by which the molecules of a substance (known as solute) disperse within another substance (known as  solvent) to give a homogeneous mixture (known as solution), in which each solute molecule is completed surrounded by solvent molecules.

If no crystals have formed by the making of solution, we must try to induce crystallization by scratching the inner side of our flask at the interface of the solution with a glass rod and wait a few more minutes. When small crystals appear, we must cool our solution on ice about 15 minutes more. Our crystals should be formed by then.

Learn more about crystals from the link given below.

https://brainly.com/question/13008800

#SPJ4

The concept Le Chatelier's principle is used here to determine the increase in the concentration of Cl₂. Here on adding more amount of O₂, the amount of Cl₂ can be increased.

If a system in equilibrium is subjected to a change in concentration, pressure or temperature, the equilibrium shifts in the direction which tends to reduce the effect of the change. This is called the Le Chatelier's principle.

In chemical equilibrium, if the concentration of any one of the reacting species is increased, the equilibrium will shift in the forward direction and more products will be formed.

Thus here on adding O₂, the amount of Cl₂ produced will be more.

To know more about Le Chatelier's principle, visit;

https://brainly.com/question/18850227

#SPJ1

Answer:decrease the volume of the container

Explanation:Acellus confirmed

If only 4 moles of ethanoic acid were found in the funnel. the equation for the reaction between ethanol and ethanoic acid to form ethyl ethanoate and water is CH3CH2OH + CH3COOH ⇌ CH3COOCH2CH3 + H2O.

a) The balanced chemical equation for the reaction between ethanol and ethanoic acid to form ethyl ethanoate and water is:

CH3CH2OH + CH3COOH ⇌ CH3COOCH2CH3 + H2O

b) To determine the number of moles of each component present at equilibrium, we can use the information given in the problem statement. Initially, we have:

5 moles of ethanol

6 moles of ethanoic acid

6 moles of ethyl ethanoate

4 moles of water

At equilibrium, we have:

4 moles of ethanoic acid (so we have lost 2 moles of ethanoic acid)

5 - x moles of ethanol (where x is the number of moles of ethanol that reacted to form ethyl ethanoate)

6 moles of ethyl ethanoate (since it is a product, the amount does not change)

4 + x moles of water (since water is also a product, its amount increases as the reaction proceeds)

Since the reaction is in stoichiometric proportions, the number of moles of ethanoic acid lost is equal to the number of moles of ethyl ethanoate and water produced. Therefore, we can set up the following equation to solve for x:

2x = 2

x = 1

Therefore, at equilibrium, we have:

4 moles of ethanoic acid

4 moles of ethanol (5 - 1)

6 moles of ethyl ethanoate

5 moles of water (4 + 1)

c) The equilibrium constant for the reaction is given by the following expression:

Kc = [CH3COOCH2CH3][H2O]/[CH3CH2OH][CH3COOH]

Plugging in the concentrations at equilibrium, we get:

Kc = [(6 mol)/(L) * 5 mol/L]/[(5 mol/L) * (4 mol/L)]

Kc = 1.5

Therefore, the equilibrium constant for this reaction is 1.5. Note that since the value of Kc is greater than 1, the reaction lies to the right at equilibrium, meaning that the formation of ethyl ethanoate is favored.

Learn more about ethanol and ethanoic acid here:https://brainly.com/question/27918265

#SPJ1

The complete question is:

5 moles of ethanol, 6 moles of ethanoic acid, 6 moles of ethyl ethanoate and 4 moles of water were mixed together in a separatory funnel at 15 ° C. After equilibration was established, only 4 moles of ethanoic acid were found in the funnel. a) Write the equation for the reaction between ethanol and ethanoic acid to form ethyl ethanoate and water. b) How many moles of ethanol, ethyl ethanoate and water are present in the equilibrium mixture? d) What is the value of the equilibrium constant for this reaction?

The best explanation for the ability of carbon to form four bonds with other atoms is option A, which states that carbon has 4 valence electrons.

Valence electrons are the outermost electrons in an atom and are involved in chemical bonding. Carbon has 6 electrons in total, with 2 in the inner shell and 4 in the outer shell. These 4 valence electrons are available for bonding with other atoms, allowing carbon to form up to four covalent bonds, either with other carbon atoms or with other elements such as hydrogen, nitrogen, and oxygen. This ability to form multiple bonds and complex structures is fundamental to the chemistry of life, allowing for the creation of diverse and complex organic molecules necessary for life processes.

Find out more about Valence electrons

brainly.com/question/1626020

#SPJ4

0.378 moles of barium chloride are needed to produce 10.5 grams of aluminum chloride.

Barium chloride is an inorganic compound with the chemical formula BaCl2. It is a white, odorless powder that is highly soluble in water. It is commonly used in industrial applications, such as water treatment, papermaking, and asphalt production.

To answer this question, you first need to calculate the molar mass of barium chloride and aluminum chloride. The molar mass of barium chloride is 208.212 g/mol and the molar mass of aluminum chloride is 133.341 g/mol.
Next, you need to calculate the moles of aluminum chloride needed to produce 10.5 grams. To do this, divide the 10.5 grams of aluminum chloride by the molar mass of aluminum chloride (133.341 g/mol), which equals 0.0788 moles of aluminum chloride.
Now, you can calculate the moles of barium chloride needed to produce the 0.0788 moles of aluminum chloride. To do this, divide the 0.0788 moles of aluminum chloride by the molar mass ratio of barium chloride to aluminum chloride (208.212 g/mol / 133.341 g/mol), which equals 0.378 moles of barium chloride.
Therefore, 0.378 moles of barium chloride are needed to produce 10.5 grams of aluminum chloride.

To learn more about barium chloride
https://brainly.com/question/20411222
#SPJ1

The system will shift to the left, consuming some of the added heat, in order to reestablish equilibrium.

If the concentration of one of the reactants was increased, the equilibrium would shift towards the products to reestablish equilibrium.

The addition of a catalyst would not affect the equilibrium of a system. It would only increase the rate at which the equilibrium is reached.

Learn more about equilibrium here:

https://brainly.com/question/30694482

#SPJ1

It would be expected that the molecule CH3CH2C=CH would exhibit moderate IR absorption compound  around 3100cm-1.

The correct answer is A

A compound is indeed a substance that consists of two or more separate chemical elements united in a certain order in chemistry. When the parts came together, they interact and create covalent bond that are challenging to break. The sharing or trading of electrons between atoms results in the formation of these bonds.

A compound is a substance formed of bound atoms from different types. Mixture: a combination comprising two or more substances that haven't chemically interacted to form bonds with one another; each component of the combination retains its own characteristics.

To know more about compound visit:

https://brainly.com/question/13516179

#SPJ4

No, I agree with this assertion. The data from the experiments show that the final pressures were not constant.

Experiments are activities designed to test a hypothesis or explore a phenomenon. Experiments involve making observations and collecting data to analyze the results. Experiments can be used in a wide range of scientific fields such as biology, physics, chemistry, and psychology. Experiments are typically designed to control variables in order to measure the effects of an independent variable on a dependent variable. Experiments are often conducted in a laboratory setting but can also be conducted in the field or in the classroom. Experiments are essential for making discoveries and advancing scientific knowledge.

In particular, the final pressures in Experiments 3 and 4 were notably lower than the final pressures of the other experiments. This suggests that the caco3(s) had not completely decomposed in those experiments.

To learn more about experiments
https://brainly.com/question/17749452
#SPJ1

HCL is a strong acid because it dissociates completely. An acid is said to be strong acid if it ionizes completely in the solution.

Acids are called as strong acids if that completely dissociate into their ions in water. That means in a solution all of their molecules break up. These acids yield at least one hydrogen cation (H+) per molecule. Weak acids will dissociate less than 1% that means very few of their molecules will break up to release a hydrogen ion. Strong acids will have large values for dissociation constant while weak acids will have very small values for dissociation constant. Strong acids are very corrosive such as hydrochloric acid and sulfuric acid. Weak acids can also be extremely corrosive such as hydrofluoric acid which can decalcify bone.

To learn more about Strong acids please visit:

https://brainly.com/question/30401504

#SPJ4

The correct question is,

Is HCL is a strong acid?

Answer:

The atomic mass of carbon-12 is exactly 12.

Explanation:

12.011 amu

All the masses of the elements are determined relative to 12C. Since many elements have a number of isotopes, chemists use average atomic mass. On the periodic table the mass of carbon is reported as 12.011 amu.

The relative atomic mass of carbon-12 is defined as exactly 12 and the relative atomic mass of carbon-13 is 13.00335. Now, you can calculate the atomic weight of carbon in the sample. For this sample, the atomic weight of carbon is 12.0107.

Now, we must first calculate the value of pOH using the provided pH value in order to get the concentration of hydroxide ions. LiOH will be the base.

The negative logarithm of the hydronium ion concentration in moles per liter is used to calculate the pH of a solution. The formula is as follows:

pH = -log [H₃O⁺]

We have the relation, pH + pOH = 14

Then pOH = 14 - pH = 14 - 12 = 2

[OH⁻] = -log [pOH]

= -log (2)

= 10⁻² M

= 0.01 M

The base's molar mass is:

[OH⁻] = Mass of the base × 1000 / Molar mass × volume

0.01 = 0.02 × 1000 / 0.01 × 83

= 24 mol / gm

LiOH thus has a molar mass of 24 mol/gm.

To learn more about pH value, refer to:

https://brainly.com/question/172153

#SPJ1

A is the best option. Dispersion forces act on both molecules, as they do on all molecules.

The least powerful intermolecular force exists through the London dispersion. When the electrons in two nearby atoms occupy positions that cause the atoms to temporarily form dipoles, a transient attractive force called the London dispersion force is created. There are occasions when this force is referred to as an induced dipole-induced dipole attraction. When the temperature is decreased enough, the attraction forces known as London forces drive nonpolar substances to condense into liquids and to freeze into solids.  Because electrons are always moving, when their distribution around the nucleus is asymmetric, an atom or molecule may suddenly generate a dipole.

The development of the dipole in the first atom or molecule might, in turn, distort a second atom or molecule because electrons repel one another, creating an electric attraction between the two atoms or molecules. Any two molecules, including polar molecules, exhibit dispersion forces when they are just inches away from one another.

Learn more about  Dispersion forces here:

https://brainly.com/question/14958417

#SPJ4

The Intermolecular Forces shared between CH₃CH₂CH₂F and CH₃CH₂CH₂OH are Dispersion forces, dipole-dipole forces, and hydrogen bonding.

CH₃CH₂CH₂F is a fluorocarbon, which is a polar molecule due to the electronegativity difference between carbon and fluorine. CH₃CH₂CH₂OH is an alcohol, which is also a polar molecule due to the presence of the highly electronegative oxygen atom.

Both molecules have dispersion forces, which are the attractive forces between temporary dipoles that result from the movement of electrons within molecules. In addition, both molecules have dipole-dipole forces, which are the attractive forces between the permanent dipoles that result from the polar nature of the molecules.

However, CH₃CH₂CH₂OH also has hydrogen bonding, which is a type of dipole-dipole force that occurs specifically between molecules that contain a hydrogen atom bonded to a highly electronegative atom such as oxygen, nitrogen, or fluorine. In CH₃CH₂CH₂OH, the hydrogen atom is bonded to the oxygen atom, which is highly electronegative, allowing for hydrogen bonding to occur.

To learn more about hydrogen bonding

https://brainly.com/question/10904296

#SPJ4

Answer: 2NH3(g) → N₂(g) +3 H₂(g)

Both sides have:

2 nitrogens

6 hydrogens

Considering the given acids in different beakers at the same pH of 3.00,

7.  All have the same hydrogen ion concentration.

The correct option is D

8. The solution that has the highest percent ionization is Beaker 1. The correct option is A.

The pH of a solution is the negative logarithm of the hydrogen ion concentration of the solution.

Since the acid solutions are all at the same pH, the hydrogen ion concentration of the solutions in the beaker is the same.

The percent ionization of acids is a measure of the number of hydrogen ions produced by 1 mole of the acid solution. Strong acids have a 1005 ionization.

Hence, HCl has the highest percent ionization of the acid solutions in the beakers,

Learn more about pH and percent ionization at: https://brainly.com/question/9080321

#SPJ1