Question 1

Which has more atoms: 64.058 g of sulfur dioxide, S   (64.058 amu), or 72.922 g of hydrogen chloride, HCl (36.461 amu)?

Accepted Answer

A) 64.058 g of S   has more atoms than 72.922 g of HCl 
B) 72.922 g of HCl has more atoms than 64.058 g of S   
C) 72.922 g of HCl and 64.058 g of S   have about the same number atoms. 
D) Not enough information is given. 
A) 64.058 g of S   has more atoms than 72.922 g of HCl 
B) 72.922 g of HCl has more atoms than 64.058 g of S   
C) 72.922 g of HCl and 64.058 g of S   have about the same number atoms. 
D) Not enough information is given.

Question 2

Seven grams of nitrogen, N2, (N, atomic mass 14 amu)contains ________.

Accepted Answer

A) 1 mole of nitrogen atoms 
B) 0.5 moles of nitrogen atoms 
C) 0.25 moles of nitrogen atoms 
D) Not enough information is given 
A) 1 mole of nitrogen atoms 
B) 0.5 moles of nitrogen atoms 
C) 0.25 moles of nitrogen atoms 
D) Not enough information is given

Question 3

What coefficient is needed in front of the O2 molecule to balance the following equation?

Accepted Answer

A) 8 
B) 13 
C) 5 
D) 1 
A) 8 
B) 13 
C) 5 
D) 1

Question 4

In a chemical equation the coefficients ________.

Accepted Answer

A) of the reactants should always sum up to those of the products 
B) appear as subscripts 
C) appear before the chemical formulas 
D) Two of the above are correct. 
A) of the reactants should always sum up to those of the products 
B) appear as subscripts 
C) appear before the chemical formulas 
D) Two of the above are correct.

Question 5

What is an endothermic reaction?

Accepted Answer

A) It is a reaction that requires heat as a reactant. 
B) It is a reaction where the products have more energy than the reactants. 
C) It is a reaction where there is a net adsorption of energy from a reaction. 
D) all of the above 
E) none of the above 
A) It is a reaction that requires heat as a reactant. 
B) It is a reaction where the products have more energy than the reactants. 
C) It is a reaction where there is a net adsorption of energy from a reaction. 
D) all of the above 
E) none of the above

Question 6

If it takes energy to break bonds and you gain energy in the formation of bonds, how can some reactions be exothermic while others are endothermic?

Accepted Answer

A) It is the total amount of energy that matters. Sometimes some bonds are stronger than others and so you gain or lose energy when you form them. 
B) It is the total number of bonds that matters. Sometimes you create more bonds than you break and since all bonds have same amount of energy you gain or lose energy depending on the number of bonds. 
C) Some reactants have more energetic bonds than others and they will always release energy. 
D) Some products have more energy than others and they always require energy to be formed. 
E) none of the above 
A) It is the total amount of energy that matters. Sometimes some bonds are stronger than others and so you gain or lose energy when you form them. 
B) It is the total number of bonds that matters. Sometimes you create more bonds than you break and since all bonds have same amount of energy you gain or lose energy depending on the number of bonds. 
C) Some reactants have more energetic bonds than others and they will always release energy. 
D) Some products have more energy than others and they always require energy to be formed. 
E) none of the above

Question 7

Which has the greatest number of atoms?

Accepted Answer

A) 28 g of nitrogen,   
B) 32 g of oxygen,   
C) 16 g of methane, C   
D) 38 g of fluorine,   
A) 28 g of nitrogen,   
B) 32 g of oxygen,   
C) 16 g of methane, C   
D) 38 g of fluorine,

Question 8

The atomic masses appearing in the periodic table are ________.

Accepted Answer

A) absolute masses 
B) relative masses 
C) standard deviation masses 
D) formula masses 
A) absolute masses 
B) relative masses 
C) standard deviation masses 
D) formula masses

Question 9

Which of the following has the greatest number of particles?

Accepted Answer

A) 1 mole of Na 
B) 22.990 g of Na 
C) 1 mole of Be 
D) 9.012 g of Be 
E) All are the same. 
A) 1 mole of Na 
B) 22.990 g of Na 
C) 1 mole of Be 
D) 9.012 g of Be 
E) All are the same.

Question 10

A refrigerator delays the spoilage of food by ________.

Accepted Answer

A) killing microorganisms 
B) slowing down the rate of chemical reactions within microorganisms 
C) expanding the water found within microorganisms 
D) diminishing the supply of oxygen to microorganisms 
A) killing microorganisms 
B) slowing down the rate of chemical reactions within microorganisms 
C) expanding the water found within microorganisms 
D) diminishing the supply of oxygen to microorganisms

Question 11

For the following balanced reaction, which of the following is a gas? 2 Na(l) + Cl2(g) → 2 NaCl(s)

Accepted Answer

A) Na 
B) 2 Na 
C) Cl2 
D) Cl 
E) NaCl 
A) Na 
B) 2 Na 
C) Cl2 
D) Cl 
E) NaCl

Question 12

The relative mass of carbon is 3/8 that of an oxygen molecule. How many grams of carbon are needed to have the same number of particles as found in 32 grams of oxygen molecules?

Accepted Answer

A) 12 g 
B) 32 g 
C) 3 g 
D) 8 g 
E) 3/8 g 
A) 12 g 
B) 32 g 
C) 3 g 
D) 8 g 
E) 3/8 g

Question 13

Wild plants readily grow "all by themselves" yet the molecules of the growing plant have less entropy than the materials used to make the plant. How is it possible for a there to be this decrease in entropy for a process that occurs all by itself?

Accepted Answer

A) A decrease in entropy does not necessarily mean that a reaction if favored to proceed on its own. It happens in this instance but not in others. 
B) There is no decrease in entropy when wild plants grow. All growing plants tend to display an increase in entropy. 
C) Wild plants don't grow "all by themselves." When we consider the entire system, including the sun, we find an overall increase in entropy. 
D) Life on Earth "arises on its own." It does not depend on entropy processes. 
A) A decrease in entropy does not necessarily mean that a reaction if favored to proceed on its own. It happens in this instance but not in others. 
B) There is no decrease in entropy when wild plants grow. All growing plants tend to display an increase in entropy. 
C) Wild plants don't grow "all by themselves." When we consider the entire system, including the sun, we find an overall increase in entropy. 
D) Life on Earth "arises on its own." It does not depend on entropy processes.

Question 14

Which has more entropy: a shuffled deck of playing cards or an unshuffled deck of the same make and brand?

Accepted Answer

A) These cards have the same entropy because they are made of the same material, have the same mass, and are at the same temperature. 
B) The shuffled deck has more entropy since it has a greater measure of disorder. 
C) The unshuffled deck has more entropy because it comes packaged with a totally random order of appearance. Shuffling the deck ultimately adds order and reduces entropy. 
D) The difference in entropy in the two decks could only be determined after examining both stacks of cards side by side once the unshuffled deck had been shuffled. 
A) These cards have the same entropy because they are made of the same material, have the same mass, and are at the same temperature. 
B) The shuffled deck has more entropy since it has a greater measure of disorder. 
C) The unshuffled deck has more entropy because it comes packaged with a totally random order of appearance. Shuffling the deck ultimately adds order and reduces entropy. 
D) The difference in entropy in the two decks could only be determined after examining both stacks of cards side by side once the unshuffled deck had been shuffled.

Question 15

Fourteen grams of nitrogen, N2, (N, atomic mass 14 amu)contains ________.

Accepted Answer

A) 1 mole of nitrogen atoms 
B) 0.5 moles of nitrogen atoms 
C) 0.25 moles of nitrogen atoms 
D) Not enough information is given 
A) 1 mole of nitrogen atoms 
B) 0.5 moles of nitrogen atoms 
C) 0.25 moles of nitrogen atoms 
D) Not enough information is given

Question 16

How is Avogadro's number related to the numbers on the periodic table?

Accepted Answer

A) The atomic mass listed is the mass of Avogadro's number's worth of atoms. 
B) The masses are all divisible by Avogadro's number, which gives you the weight of one mole. 
C) The periodic table tells you the mass of one atom. From that, and Avogadro's number you know the number of moles. 
D) The periodic table only gives us atomic numbers, not atomic mass. 
E) The mass listed is Avogadro's number. 
A) The atomic mass listed is the mass of Avogadro's number's worth of atoms. 
B) The masses are all divisible by Avogadro's number, which gives you the weight of one mole. 
C) The periodic table tells you the mass of one atom. From that, and Avogadro's number you know the number of moles. 
D) The periodic table only gives us atomic numbers, not atomic mass. 
E) The mass listed is Avogadro's number.

Question 17

What is the number of moles of H2O produced if you combust one mole of CH4 according to the following balanced equation? CH4 + 2 O2 → CO2 + 2 H2O

Accepted Answer

A) 2 moles 
B) 4 moles 
C) 6 moles 
D) 8 moles 
E) 1 mole 
A) 2 moles 
B) 4 moles 
C) 6 moles 
D) 8 moles 
E) 1 mole

Question 18

What is the mass of a water molecule,   O, in atomic mass units?

Accepted Answer

A) 2 amu 
B) 3 amu 
C) 16 amu 
D) 18 amu 
A) 2 amu 
B) 3 amu 
C) 16 amu 
D) 18 amu

Question 19

How many grams of water, H2O, can be produced by the reaction of 8 grams of oxygen, O2, and 8 grams of hydrogen, H2?

Accepted Answer

A) 16 grams 
B) 10 grams 
C) 9 grams 
D) 8 grams 
A) 16 grams 
B) 10 grams 
C) 9 grams 
D) 8 grams

Question 20

Why might increasing the concentration of a set of reactants increase the rate of reaction?

Accepted Answer

A) You have increased the chances that any two reactant molecules will collide and react. 
B) You have increased the ratio of reactants to products. 
C) The concentration of reactants is unrelated to the rate of reaction. 
D) The rate of reaction depends only on the mass of the atoms and therefore increases as you increase the mass of the reactants. 
E) none of the above 
A) You have increased the chances that any two reactant molecules will collide and react. 
B) You have increased the ratio of reactants to products. 
C) The concentration of reactants is unrelated to the rate of reaction. 
D) The rate of reaction depends only on the mass of the atoms and therefore increases as you increase the mass of the reactants. 
E) none of the above

Which has more atoms: 64.058 g of sulfur dioxide, S (64.058 amu), or 72.922 g of hydrogen chloride, HCl (36.461 amu)?

Seven grams of nitrogen, N₂, (N, atomic mass 14 amu)contains ________.

What coefficient is needed in front of the O₂ molecule to balance the following equation?

In a chemical equation the coefficients ________.

What is an endothermic reaction?

If it takes energy to break bonds and you gain energy in the formation of bonds, how can some reactions be exothermic while others are endothermic?

Which has the greatest number of atoms?

The atomic masses appearing in the periodic table are ________.

Which of the following has the greatest number of particles?

A refrigerator delays the spoilage of food by ________.

For the following balanced reaction, which of the following is a gas? 2 Na_(l) + Cl_2(g) → 2 NaCl_(s)

The relative mass of carbon is 3/8 that of an oxygen molecule. How many grams of carbon are needed to have the same number of particles as found in 32 grams of oxygen molecules?

Wild plants readily grow "all by themselves" yet the molecules of the growing plant have less entropy than the materials used to make the plant. How is it possible for a there to be this decrease in entropy for a process that occurs all by itself?

Which has more entropy: a shuffled deck of playing cards or an unshuffled deck of the same make and brand?

Fourteen grams of nitrogen, N₂, (N, atomic mass 14 amu)contains ________.

How is Avogadro's number related to the numbers on the periodic table?

What is the number of moles of H₂O produced if you combust one mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

What is the mass of a water molecule, O, in atomic mass units?

How many grams of water, H₂O, can be produced by the reaction of 8 grams of oxygen, O₂, and 8 grams of hydrogen, H₂?

Why might increasing the concentration of a set of reactants increase the rate of reaction?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Water Behaves

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

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Exam 9: How Chemicals React

Which has more atoms: 64.058 g of sulfur dioxide, S (64.058 amu), or 72.922 g of hydrogen chloride, HCl (36.461 amu)?

Seven grams of nitrogen, N2, (N, atomic mass 14 amu)contains ________.

What coefficient is needed in front of the O2 molecule to balance the following equation?

In a chemical equation the coefficients ________.

What is an endothermic reaction?

If it takes energy to break bonds and you gain energy in the formation of bonds, how can some reactions be exothermic while others are endothermic?

Which has the greatest number of atoms?

The atomic masses appearing in the periodic table are ________.

Which of the following has the greatest number of particles?

A refrigerator delays the spoilage of food by ________.

For the following balanced reaction, which of the following is a gas? 2 Na(l) + Cl2(g) → 2 NaCl(s)

The relative mass of carbon is 3/8 that of an oxygen molecule. How many grams of carbon are needed to have the same number of particles as found in 32 grams of oxygen molecules?

Wild plants readily grow "all by themselves" yet the molecules of the growing plant have less entropy than the materials used to make the plant. How is it possible for a there to be this decrease in entropy for a process that occurs all by itself?

Which has more entropy: a shuffled deck of playing cards or an unshuffled deck of the same make and brand?

Fourteen grams of nitrogen, N2, (N, atomic mass 14 amu)contains ________.

How is Avogadro's number related to the numbers on the periodic table?

What is the number of moles of H2O produced if you combust one mole of CH4 according to the following balanced equation? CH4 + 2 O2 → CO2 + 2 H2O

What is the mass of a water molecule, O, in atomic mass units?

How many grams of water, H2O, can be produced by the reaction of 8 grams of oxygen, O2, and 8 grams of hydrogen, H2?

Why might increasing the concentration of a set of reactants increase the rate of reaction?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Water Behaves

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

Seven grams of nitrogen, N₂, (N, atomic mass 14 amu)contains ________.

What coefficient is needed in front of the O₂ molecule to balance the following equation?

For the following balanced reaction, which of the following is a gas? 2 Na_(l) + Cl_2(g) → 2 NaCl_(s)

Fourteen grams of nitrogen, N₂, (N, atomic mass 14 amu)contains ________.

What is the number of moles of H₂O produced if you combust one mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

How many grams of water, H₂O, can be produced by the reaction of 8 grams of oxygen, O₂, and 8 grams of hydrogen, H₂?