Question 1

Can a catalyst react with a reactant? Why or why not?

Accepted Answer

A) No. A catalyst doesn't react with anything. 
B) No. A catalyst is really not part of the reaction. 
C) Yes. A catalyst's job is to provide more product than could be produced in a uncatalyzed reaction. 
D) Yes. A catalyst reacts with a reactant to form an intermediate. 
A) No. A catalyst doesn't react with anything. 
B) No. A catalyst is really not part of the reaction. 
C) Yes. A catalyst's job is to provide more product than could be produced in a uncatalyzed reaction. 
D) Yes. A catalyst reacts with a reactant to form an intermediate.

Question 2

An Alka-Seltzer antacid tablet bubbles vigorously when placed in water but only slowly when placed in an alcoholic beverage of the same temperature containing a 50:50 mix of alcohol and water. Propose a probable explanation involving the relationship between the speed of a reaction and molecular collisions.

Accepted Answer

A) The alcohol absorbs the carbon dioxide bubbles before they escape the liquid phase. 
B) Alcohol molecules are more massive than water molecules, hence they move slower and their collisions are not as forceful. 
C) The tablet reacts with water but not the alcohol. 
D) In a 50:50 mix there are fewer water molecules for the antacid molecules to collide with. 
A) The alcohol absorbs the carbon dioxide bubbles before they escape the liquid phase. 
B) Alcohol molecules are more massive than water molecules, hence they move slower and their collisions are not as forceful. 
C) The tablet reacts with water but not the alcohol. 
D) In a 50:50 mix there are fewer water molecules for the antacid molecules to collide with.

Question 3

Bond energies increase in going from C-N (lowest)to C-O to C-F (highest). Explain this trend based upon the atomic sizes of these atoms as deduced from their positions in the periodic table.

Accepted Answer

A) In going from nitrogen to oxygen to fluorine the atoms get larger. This means a greater nuclear charge, which translates into stronger chemical bonds. 
B) In going from nitrogen to oxygen to fluorine the atoms get smaller. This means a greater nuclear charge, which translates into stronger chemical bonds. 
C) In going from nitrogen to oxygen to fluorine the atoms get larger. This means that the bonding atoms are farther apart, which translates into a greater bond energy. 
D) In going from nitrogen to oxygen to fluorine the atoms get smaller. This means that the bonding atoms are closer together, which translates into a greater bond energy. 
A) In going from nitrogen to oxygen to fluorine the atoms get larger. This means a greater nuclear charge, which translates into stronger chemical bonds. 
B) In going from nitrogen to oxygen to fluorine the atoms get smaller. This means a greater nuclear charge, which translates into stronger chemical bonds. 
C) In going from nitrogen to oxygen to fluorine the atoms get larger. This means that the bonding atoms are farther apart, which translates into a greater bond energy. 
D) In going from nitrogen to oxygen to fluorine the atoms get smaller. This means that the bonding atoms are closer together, which translates into a greater bond energy.

Question 4

Why might increasing the temperature alter the rate of a chemical reaction?

Accepted Answer

A) The molecules will have a higher kinetic energy and bump into one another harder. 
B) The molecules are less reactive at higher temperatures. 
C) The molecules will more likely combine with other atoms at high temperature to save space. 
D) The density decreases as a function of temperature and this leads to an increase in volume which drops the rate of reaction. 
E) none of the above 
A) The molecules will have a higher kinetic energy and bump into one another harder. 
B) The molecules are less reactive at higher temperatures. 
C) The molecules will more likely combine with other atoms at high temperature to save space. 
D) The density decreases as a function of temperature and this leads to an increase in volume which drops the rate of reaction. 
E) none of the above

Question 5

The above diagram represents a chemical reaction where the box before the arrow shows the reactants and the box after the arrow shows the products. How many diatomic molecules are represented?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
A) 1 
B) 2 
C) 3 
D) 4

Question 6

Given that the above energy profiles have the same scale, which of the reactions would require the most energy?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) none of the above 
A) a 
B) b 
C) c 
D) d 
E) none of the above

Question 7

Why is there a drastic reduction in ozone in the spring?

Accepted Answer

A) There is a sudden increase in Cl atoms in the spring. 
B) It is warmer in the spring. 
C) There are more chlorofluorocarbons in the spring. 
D) all of the above 
E) only a and b 
A) There is a sudden increase in Cl atoms in the spring. 
B) It is warmer in the spring. 
C) There are more chlorofluorocarbons in the spring. 
D) all of the above 
E) only a and b

Question 8

Which of the following statements is not in line with the concepts of thermodynamics?

Accepted Answer

A) Energy has a tendency to stay in one place. 
B) Energy is neither created nor destroyed. 
C) The entropy of the universe is constantly increasing. 
D) The energy released in a chemical reaction is the same as the difference in the energy of the bonds broken and formed. 
E) All of the above describe the concepts of thermodynamics. 
A) Energy has a tendency to stay in one place. 
B) Energy is neither created nor destroyed. 
C) The entropy of the universe is constantly increasing. 
D) The energy released in a chemical reaction is the same as the difference in the energy of the bonds broken and formed. 
E) All of the above describe the concepts of thermodynamics.

Question 9

Given the following energy profiles, which of the following reactions is endothermic?   R= reactants P= products

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) none of the above 
A) a 
B) b 
C) c 
D) d 
E) none of the above

Question 10

How does a catalyst increase the rate of a reaction?

Accepted Answer

A) It lowers the activation energy. 
B) It is neither created nor consumed in a reaction. 
C) It has nothing to do with the rate of reaction. 
D) It increases the energy difference between the reactants and products. 
E) It raises the activation energy of the reactants, which makes the reaction proceed faster. 
A) It lowers the activation energy. 
B) It is neither created nor consumed in a reaction. 
C) It has nothing to do with the rate of reaction. 
D) It increases the energy difference between the reactants and products. 
E) It raises the activation energy of the reactants, which makes the reaction proceed faster.

Question 11

How many grams of water,   O, and propene,     , can be formed from the reaction of 6.0 g of 2-propanol,     O?     O →     +   O 2-Propanol Propene Water

Accepted Answer

A) 6.0 grams of propene, 0.0 grams of water 
B) 1.8 grams of propene, 4.2 grams of water 
C) 0.0 grams of propene, 6.0 grams of water 
D) 4.2 grams of propene, 1.8 grams of water 
A) 6.0 grams of propene, 0.0 grams of water 
B) 1.8 grams of propene, 4.2 grams of water 
C) 0.0 grams of propene, 6.0 grams of water 
D) 4.2 grams of propene, 1.8 grams of water

Question 12

What is the formula mass of a molecule of C6H12O6?

Accepted Answer

A) 180 amu 
B) 24 amu 
C) 29 amu 
D) 168 amu 
E) none of the above 
A) 180 amu 
B) 24 amu 
C) 29 amu 
D) 168 amu 
E) none of the above

Question 13

What is the mass of a water molecule,   O, in grams? (1 amu = 1.661 × 10-24 g)

Accepted Answer

A) 18 grams 
B) 1.661 ×   grams 
C) 2.99 × 10-23 grams 
D) none of the above 
A) 18 grams 
B) 1.661 ×   grams 
C) 2.99 × 10-23 grams 
D) none of the above

Question 14

What is the mass of an oxygen atom, O, in grams? (1 amu = 1.661 × 10-24 g)

Accepted Answer

A) 16 grams 
B) 1.661 ×   grams 
C) 2.66 ×   grams 
D) none of the above 
A) 16 grams 
B) 1.661 ×   grams 
C) 2.66 ×   grams 
D) none of the above

Question 15

What is the mass of an oxygen atom, O, in atomic mass units?

Accepted Answer

A) 12 amu 
B) 16 amu 
C) 18 amu 
D) 32 amu 
A) 12 amu 
B) 16 amu 
C) 18 amu 
D) 32 amu

Question 16

Assume air has an average molar mass of 28 grams/mole, and determine how many moles of air molecules there are 1.0 liters of air, which contains 1.26 grams of air molecules.

Accepted Answer

A) 28 moles 
B) 0.45 mole 
C) 0.045 mole 
D) 22.4 moles 
A) 28 moles 
B) 0.45 mole 
C) 0.045 mole 
D) 22.4 moles

Question 17

What is a chemical equation?

Accepted Answer

A) It is a shorthand notation for illustrating a chemical reaction. 
B) It is the sum of the masses of the products and reactants. 
C) It is the chemical combination of equal numbers of reactants and products. 
D) It is a picture of the atoms undergoing a chemical equalization. 
E) It is any type of reaction that takes place at the equator. 
A) It is a shorthand notation for illustrating a chemical reaction. 
B) It is the sum of the masses of the products and reactants. 
C) It is the chemical combination of equal numbers of reactants and products. 
D) It is a picture of the atoms undergoing a chemical equalization. 
E) It is any type of reaction that takes place at the equator.

Question 18

Why does iodine,   (s), spontaneously sublime at room temperature?

Accepted Answer

A) The contact of iodine,   (s), with the water vapor in the air causes the sublimation process. 
B) Iodine,   (s), pulls   from the air as it self-oxidizes under sublimation to   (g). 
C) There is an increase in entropy as solid iodine,   (s), sublimes into iodine vapor,   (g), because in the gaseous phase energy is more readily dispersed. 
D) The reaction of   (s)subliming to   (g)is highly exothermic and therefore proceeds spontaneously. 
A) The contact of iodine,   (s), with the water vapor in the air causes the sublimation process. 
B) Iodine,   (s), pulls   from the air as it self-oxidizes under sublimation to   (g). 
C) There is an increase in entropy as solid iodine,   (s), sublimes into iodine vapor,   (g), because in the gaseous phase energy is more readily dispersed. 
D) The reaction of   (s)subliming to   (g)is highly exothermic and therefore proceeds spontaneously.

Question 19

What is an exothermic 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 20

Steel wool wetted with vinegar is sealed within a balloon inflated with air. After several hours, what happens to the volume of the balloon?

Accepted Answer

A) The balloon inflates. 
B) The balloon deflates. 
C) The balloon dissolves. 
D) Nothing because the vinegar is acting on the steel wool, not upon the balloon. 
A) The balloon inflates. 
B) The balloon deflates. 
C) The balloon dissolves. 
D) Nothing because the vinegar is acting on the steel wool, not upon the balloon.

Can a catalyst react with a reactant? Why or why not?

Bond energies increase in going from C-N (lowest)to C-O to C-F (highest). Explain this trend based upon the atomic sizes of these atoms as deduced from their positions in the periodic table.

Why might increasing the temperature alter the rate of a chemical reaction?

The above diagram represents a chemical reaction where the box before the arrow shows the reactants and the box after the arrow shows the products. How many diatomic molecules are represented?

Given that the above energy profiles have the same scale, which of the reactions would require the most energy?

Why is there a drastic reduction in ozone in the spring?

Which of the following statements is not in line with the concepts of thermodynamics?

Given the following energy profiles, which of the following reactions is endothermic? R= reactants P= products

How does a catalyst increase the rate of a reaction?

How many grams of water, O, and propene, , can be formed from the reaction of 6.0 g of 2-propanol, O? O → + O 2-Propanol Propene Water

What is the formula mass of a molecule of C₆H₁₂O₆?

What is the mass of a water molecule, O, in grams? (1 amu = 1.661 × 10^-24 g)

What is the mass of an oxygen atom, O, in grams? (1 amu = 1.661 × 10^-24 g)

What is the mass of an oxygen atom, O, in atomic mass units?

Assume air has an average molar mass of 28 grams/mole, and determine how many moles of air molecules there are 1.0 liters of air, which contains 1.26 grams of air molecules.

What is a chemical equation?

Why does iodine, (s), spontaneously sublime at room temperature?

What is an exothermic reaction?

Steel wool wetted with vinegar is sealed within a balloon inflated with air. After several hours, what happens to the volume of the balloon?

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

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Exam 9: How Chemicals React

Can a catalyst react with a reactant? Why or why not?

Bond energies increase in going from C-N (lowest)to C-O to C-F (highest). Explain this trend based upon the atomic sizes of these atoms as deduced from their positions in the periodic table.

Why might increasing the temperature alter the rate of a chemical reaction?

The above diagram represents a chemical reaction where the box before the arrow shows the reactants and the box after the arrow shows the products. How many diatomic molecules are represented?

Given that the above energy profiles have the same scale, which of the reactions would require the most energy?

Why is there a drastic reduction in ozone in the spring?

Which of the following statements is not in line with the concepts of thermodynamics?

Given the following energy profiles, which of the following reactions is endothermic? R= reactants P= products

How does a catalyst increase the rate of a reaction?

How many grams of water, O, and propene, , can be formed from the reaction of 6.0 g of 2-propanol, O? O → + O 2-Propanol Propene Water

What is the formula mass of a molecule of C6H12O6?

What is the mass of a water molecule, O, in grams? (1 amu = 1.661 × 10-24 g)

What is the mass of an oxygen atom, O, in grams? (1 amu = 1.661 × 10-24 g)

What is the mass of an oxygen atom, O, in atomic mass units?

Assume air has an average molar mass of 28 grams/mole, and determine how many moles of air molecules there are 1.0 liters of air, which contains 1.26 grams of air molecules.

What is a chemical equation?

Why does iodine, (s), spontaneously sublime at room temperature?

What is an exothermic reaction?

Steel wool wetted with vinegar is sealed within a balloon inflated with air. After several hours, what happens to the volume of the balloon?

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

What is the formula mass of a molecule of C₆H₁₂O₆?

What is the mass of a water molecule, O, in grams? (1 amu = 1.661 × 10^-24 g)

What is the mass of an oxygen atom, O, in grams? (1 amu = 1.661 × 10^-24 g)