Answer:
the answer would be B
Explanation:
The power from the charger use electricity and the electricity transforms to energy that can be moved
How many moles of KOH are in 21.0g of KOH?
Answer:
HowHow many moles of KOH are in 21.0g of KOH?
Answer:
0.374 moles
Explanation:
I have included the dimensional analysis below, and by MM I mean Molar Mass of the atom.
Hope this helps!
GIVING BRAINLY AND 20 POINTS
A sound wave in air has the wavelength of 1.36 m. Calculate its frequency? Assume the speed is 340 m/s.
Explanation:
frequency= velocity/ wavelength
= 340/1.36
=250
________ are neutral particles found in the nucleus of an atom.
A compound consists of 75% magnesium and 25% oxygen. Find the empirical formula.
% Composition of elements:
Magnesium = 75%Oxygen = 25%Atomic mass of given elements:
Magnesium = 24 gOxygen = 16 gNow, divide % composition by Atomic mass:
[tex]\footnotesize\implies Mg = \dfrac{\% \: Composition}{Atomic \: mass} = \dfrac{75}{24} = \bf 3.125[/tex]
[tex]\footnotesize\implies O = \dfrac{\% \: Composition}{Atomic \: mass} = \dfrac{25}{16} = \bf 1.5625[/tex]
Simplest Ratio:
[tex]\footnotesize\implies Mg = \dfrac{3.125}{1.5625} = 2[/tex]
[tex]\footnotesize\implies O = \dfrac{1.5625}{1.5625} = 1[/tex]
Empirical Formula:
[tex]\footnotesize\implies \underline{ \boxed{ \red{ \bf Empirical \: Formula = Mg_2O}}}[/tex]
The empirical formula will be [tex]Mg_{2}[/tex] .
What is empirical formula?The simplest entire number fraction of atoms contained in a chemical molecule is its empirical formula.
Calculation of empirical formula:
It is given that, composition of Mg = 75 %, composition of oxygen = 25%.
It is known that, atomic mass of Mg = 24 g, atomic mass of oxygen = 16g.
By dividing % composition by atomic mass of given elements:
Mg = % composition / %atomic mass
= 75 / 24
= 3.125
Oxygen (O) = % Composition / atomic mass
= 25 / 1.56
Now, calculate simplest ratio of Mg and O.
For Mg = 3.125 / 1.56
= 2.
For O = 1.56 / 1.56
= 1
So, the empirical formula will be [tex]Mg_{2}O[/tex].
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Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Ni and H+ in the balanced reaction? Ni2+(aq) + NH4+(aq) → Ni(s) + NO3-(aq)
In this case, the problem is asking for the balance of a redox reaction in acidic media, in which nickel is reduced to a metallic way and nitrogen oxidized to an ionic way.
Thus, according to the given information, it turns out possible for us to balance this equation in acidic solution by firstly setting up the half reactions:
[tex]Ni^{2+}+2e^-\rightarrow Ni^0\\\\N^{3-}H_4^++3H_2O\rightarrow N^{5+}O_3^-+8e^-+10H^+[/tex]
Next, we cross multiply each half-reaction by the other's carried electrons:
[tex]8Ni^{2+}+16e^-\rightarrow 8Ni^0\\\\2N^{3-}H_4^++6H_2O\rightarrow 2N^{5+}O_3^-+16e^-+20H^+[/tex]
Finally, we add them together to obtain:
[tex]8Ni^{2+}+2N^{3-}H_4^++6H_2O\rightarrow 8Ni^0+2N^{5+}O_3^-+20H^+[/tex]
Which can be all simplified by a factor of 2 to obtain:
[tex]4Ni^{2+}+N^{3-}H_4^++3H_2O\rightarrow 4Ni^0+N^{5+}O_3^-+10H^+\\\\4Ni^{2+}(aq)+NH_4^+(aq)+3H_2O(l)\rightarrow 4Ni(s)+NO_3^-(aq)+10H^+(aq)[/tex]
Hence, the coefficients in front of Ni and H⁺ are 4 and 10 respectively.
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https://brainly.com/question/14965625What will happen to the temperature of an object if the kinetic energy of the particles increases?
The temperature of an object will increase if the kinetic energy of the particle increases.
Kinetic energy is an energy that is said to be in motion. According to the kinetic molecular theory of ideal gas, the particles of the gas are usually moving in constant random motion and they exert no force on each other.
Also, the temperature varies directly proportional to the average kinetic energy of the gas particles. As a result, when the kinetic energy of the particles increases, the temperature will also increase.
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A mixture is made of 40 ml of salt water to 200 ml of solution. What percent of the solution is salt water?
Answer:
16.7%
Explanation:
40 ml of salt water + 200 ml of solution = 240 ml
40/240 = 4/24 = 1/6=16.7%
Calculate the percent by mass of each element in LiClO2.
% Li:
% Cl:
% O:
ok done. Thank to me :>
Answer: Mass percent of Li: total mass Li = 6.94 g/mol. % Li = mass Li mass LiClO 2 × 100 % Li = 6 . ...
Mass percent of Cl: total mass Cl = 35.45 g/mol. % Cl = mass Cl mass LiClO 2 × 100 % Cl = 35 . ...
Mass percent of O: total mass O = 32.00 g/mol.
Explanation:
How do you convert a temperature from Celsius to kelvin?
Answer:
Kelvin = Celsius + 273.15
Explanation:
Instead of 273.15 you can use just 273 as well
Using the combined gas
law, what is the final
volume of the Helium gas?
This is the answer i hope it helps
A sample of gas has Pi = 0.768 ATM, Vi = 10.5 L, and Ti = 300 K. What is the final pressure if VF = 7.85 L and T and f = 250 K?
Question 1
Which of the following describes the movement of molecules in a solid?
O Molecules are stationary.
O Molecules vibrate in fixed positions.
O Molecules move fast enough to change position.
O Molecules move freely.
Please help ASAP!!!
Answer:
Molecules vibrate in a fixed position.
Explanation:
first one is just wrong.
third is liquid
fourth is gas
What is the mass in grams of one mole of sulfur? (round to 3 sig figs)
Answer:
This tells you that one mole of sulfur atoms, S , has a mass of 32 g
Which of the following is NOT a type of evidence indicating that a chemical change has occurred? *
- fizzing/bubbling
- heat is released
- solubility
- sound is given off
Answer:
sound is given off
Explanation:
due to a number of scientific research sound that is given off of an object is not due to a chemical reaction.
The sum of the number of proteins and neutrons in an atoms nucleus is its __________ ___________.
Answer:
Mass Number
Explanation:
In nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.
Please vote brainliest!
The boiling point of a substance is tested. After 10 tests, the result is given as 37+/−3°C. Which conclusion can be drawn from this result? (1 point)
The scientists do not need to collect more data because they have narrowed down the range of the results.
The scientists should not report these results until they have the exact number.
The actual boiling point is either 34°C or 40°C.
The actual boiling point is probably between 34°C and 40°C.
Answer:
Explanation:
The actual boiling point is probably between 34C and 40C.
Temperature measures the average kinetic energy of particles of the substances. Therefore, the correct option is option D that is the actual boiling point is probably between 34°C and 40°C.
What is temperature?Temperature is used to measure degree or intensity of heat of a particular substance. Temperature is measured by an instrument called thermometer.
Temperature can be measured in degree Celsius °c, Kelvin k or in Fahrenheit. Temperature is a physical quantity. Heat always flow from higher temperature source to lower temperature source.
We can convert these units of temperature into one another. The relationship between degree Celsius and Fahrenheit can be expressed as:
°C={5(°F-32)}÷9
The actual boiling point is probably between 34°C and 40°C.
Therefore, the correct option is option D.
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Al2(SO3)3
a. Count the number of Sulfur atom
b. How many total atoms are given in the compound
Please helppp
Answer:
from the words below underline six example of rhetorical patterns
Given the ionic formula below, what is the charge on ion X? Be sure to
include the sign (+ or -). Li2 x
Answer:Charge on X = (+ 2)
Explanation:
Charge on one Cl = -1
So Charge on two Cl = -2
The molecule = Neutral = 0 charge
So, to make total charge = 0 , the X should have +2 charge
XCl2 = +2 -2 = 0
X = +2
Alkaline earth metals(Be , Mg , Ca , Sr) form such type of compounds
Explanation:
When two volumes of hydrogen gas react with one volume of oxygen gas, two
volumes of gaseous water are formed. Modify the diagram you made for #2 to
represent molecules of hydrogen, oxygen and water in this reaction
During __________ reproduction, an identical copy of the parent is produced.
Answer:
During __asexual________ reproduction, an identical copy of the parent is produced.
Select all of the true statements about hydrocarbon structure.
a. Every hydrocarbon molecule is exactly the same as every other one.
b. The ability of carbon atoms to bond strongly to each other allows them to stably form ringed structures.
c. Hydrocarbons contain only single bonds that easily break down into smaller compounds.
d. Hydrocarbons are organic chemical compounds that consist of carbon and hydrogen.
Answer:
C
Explanation:
Organic compounds are the compounds which are made only from carbon and hydrogen. The correct option is option D that is hydrocarbons are organic chemical compounds that consist of carbon and hydrogen.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
There are two types of compound covalent compound and ionic in chemistry, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Hydrocarbons are organic compound. Hydrocarbon can have linear chain structure, ring structure or branched structure.
Therefore, hydrocarbons are organic chemical compounds that consist of carbon and hydrogen. The correct option is option D.
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i want help with these questions thanks !
Answer:
I will give you hints, as follows:
Explanation:
- two words: climate change
- methane smells funny
- the number of electric cars sold each year is increasing
- there´s a reason they´re call "renewable"
- GEOmetry, GEOlogy, GEOthermal
Hope this helps!
For the given reactions determine if the entropy increases or decreases.
A) 2 KClO3 (s)⇌2 KCl (s)+3 O2 (g)
B) CoCl2 (s)+6 H2O (g)⇌CoCl2⋅6H2O
Entropy increases in reaction 1 due to increase in the number of particles while entropy decreases in reaction 2 due to decrease in the number of particles.
Entropy refers to the degree of disorderliness in a system. The higher the entropy, the more disorderly the system is and the lower the entropy, the less disorderly the system is. We must note that entropy increases with increase in the number of particles.
In the reaction, 2 KClO3 (s)⇌2 KCl (s)+3 O2 (g), entropy increases because one of the products is a gas and the number of particles increases from left to right. In the second reaction, CoCl2 (s)+6 H2O (g)⇌CoCl2⋅6H2O, entropy decreases because the number of particles decreases.
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7. What's the structure of methane, CH,? Is it polar or non-polar?
O A. Trigonal planar, polar
O B. Tetrahedral, polar
O C. Trigonal planar, non-polar
O D. Tetrahedral, non-polar
Answer:
The answer is D.
Explanation:
Methane (CH4) is a non-polar hydrocarbon molecule made of a single carbon atom and four hydrogen atoms. It is found in nature in the form of natural gas. It is non-polar because the difference in electronegativities between carbon and hydrogen is not sufficient to produce a polarized chemical connection between these two elements.
The methane molecule has a tetrahedral structure in terms of molecular geometry. Because the molecule is not planar, the angles between the H-C-H bonds are 109.5°, which is more than the 90° that they would be if the molecule were planar.
Explanation:
tetrahedral, non polar
Which spheres include the water cycle? (Select all that apply.)
biosphere
geosphere
hydrosphere
atmosphere
Answer:
A, B, C, D
Explanation:
The water cycle is included in the atmosphere (water vapor in the air), the geosphere (water collection), the hydrosphere (water on earth: lakes, oceans, rivers), and the biosphere (where water interacts with all living things).
In an ecosystem, the water cycle is included in all the spheres that is biosphere,geosphere,hydrosphere and atmosphere.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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Find the volume of 0.170 M sulfuric acid necessary to react completely with 72.2 g sodium hydroxide.
The volume of sulphuric acid, H₂SO₄ needed for the complete reaction with 72.2 g of sodium hydroxide, NaOH is 5.31 L
We'll begin by calculating the number of mole in 72.2 g of NaOH. This can be obtained as follow:
Mass of NaOH = 72.2 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mole of NaOH =?Mole = mass / molar mass
Mole of NaOH = 72.2 / 40
Mole of NaOH = 1.805 mole Next, we shall determine the number of mole of H₂SO₄ needed to react with 1.805 mole of NaOH.2NaOH + H₂SO₄ —> Na₂SO₄ + 2H₂O
From the balanced equation above,
2 moles of NaOH reacted with 1 mole of H₂SO₄.
Therefore,
1.805 mole of NaOH will react with = 1.805 / 2 = 0.9025 mole of H₂SO₄.
Finally, we shall determine the volume of H₂SO₄.Mole of H₂SO₄ = 0.9025 mole
Molarity of H₂SO₄ = 0.170 M
Volume of H₂SO₄ =?Volume = mole / Molarity
Volume of H₂SO₄ = 0.9025 / 0.170
Volume of H₂SO₄ = 5.31 LThus, the volume of H₂SO₄ needed for the reaction is 5.31 L
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One night a student notices that one-quarter of the moon is visible. What is the likely explanation for this view?
If a student notices that one-quarter of the moon is visible, a lunar eclipse has taken place.
Eclipse is said to occur when one of the heavenly bodies casts a shadow on another heavenly body causing it to be partly visible or completely invisible. When the earth comes between the sun and the moon, a lunar eclipse is said to occur.
When a lunar eclipse occurs, the moon may be partly visible or completely invisible. Therefore, if a student notices that one-quarter of the moon is visible, a lunar eclipse has taken place.
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If the pressure of 50.0 mL of oxygen gas at 100°C increases from 735 mm Hg to 925 mm Hg, what is
the final volume? Assume temperature remains constant.
Answer: .039L
Explanation:
4.What volume of hydrogen gas at STP is produced when 2.5 grams of zinc react with an
excess of hydrochloric acid?
Answer:
0.86
Explanation:
1mol of Zn has mass of 65.39g.The amount of Zn is 2.5g65.39g/mol=0.038mol.
The amount of H2 produced is the same as the amount of Zn consumed (0.038mol).
1mol of ideal gas will occupy 22.4L at STP.
The H2 will occupy 0.038mol×22.4L/mol=0.86L
.
describe radioisotope
Answer:
It is an unstable form of a chemical element that releases radiation as it breaks down and becomes more stable.
A student mixes some soap with water and then blows through a straw into the solution. Bubbles form. Do you think a chemical change has taken place? Explain
Answer:
No it has not.
Explanation:
The actual chemical compound has not changed, the materials have mixed but no reaction has taken place. Blowing the bubbles causes a physical change. Hope this helped!
Mixing soap and water and forming bubbles is a physical change as there is no change in composition.
What is a physical change?
Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.
Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.
They involve only rearrangement of atoms and are often characterized to be changes which are reversible.
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