Question 1

Which of the following statements about catalysts is NOT true?

Accepted Answer

A) A catalyst alters the rate of a chemical reaction. 
B) A catalyst can be consumed in a reaction as long as it is regenerated. 
C) A catalyst can be used to speed up slow reactions. 
D) A catalyst does not change the energy of the reactants or the products. 
E) All of the above are true. 
A) A catalyst alters the rate of a chemical reaction. 
B) A catalyst can be consumed in a reaction as long as it is regenerated. 
C) A catalyst can be used to speed up slow reactions. 
D) A catalyst does not change the energy of the reactants or the products. 
E) All of the above are true. E

Question 2

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 A

Question 3

What is the main difficulty in trying to eliminate chlorinated fluorocarbons from the atmosphere?

Accepted Answer

A) They are very stable and take a long time to decompose completely. 
B) They are too light and blow away. 
C) They do not absorb ultraviolet radiation. 
D) all of the above 
E) only a and b 
A) They are very stable and take a long time to decompose completely. 
B) They are too light and blow away. 
C) They do not absorb ultraviolet radiation. 
D) all of the above 
E) only a and b A

Question 4

Given the following generic chemical reaction,which is the product? X → Y

Accepted Answer

A) Y is the product. 
B) X is the product. 
C) → is the product. 
D) Both X and Y are the products. 
E) Both X and Y are the reactants. 
A) Y is the product. 
B) X is the product. 
C) → is the product. 
D) Both X and Y are the products. 
E) Both X and Y are the reactants.

Question 5

-How many diatomic molecules are represented in the illustration above?

Accepted Answer

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

Question 6

Which is higher in an endothermic reaction: the potential energy of the reactants or the potential energy of the products?

Accepted Answer

A) The potential energy of the products is higher than the potential energy of the reactants. 
B) The potential energy of the reactants is higher than the potential energy of the products. 
C) The potential energy of the reactants is the same as the potential energy of the products. 
D) In the early stages of the reaction the potential energy of the reactants is higher.In the later stages,the potential energy of the products is higher. 
A) The potential energy of the products is higher than the potential energy of the reactants. 
B) The potential energy of the reactants is higher than the potential energy of the products. 
C) The potential energy of the reactants is the same as the potential energy of the products. 
D) In the early stages of the reaction the potential energy of the reactants is higher.In the later stages,the potential energy of the products is higher.

Question 7

If the relative mass of a pingpong ball is 1/20 that of a golf ball,how many pingpong balls would you need to equal the mass of two golf balls?

Accepted Answer

A) 40 
B) 20 
C) 24 
D) 100 
E) 6.022 × 1023 
A) 40 
B) 20 
C) 24 
D) 100 
E) 6.022 × 1023

Question 8

-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 9

-Which equation best describes the reaction represented in the illustration above?

Accepted Answer

A) 2 $\mathrm { AB } _ { 2 }$ + 2 $\mathrm { DCB } _ { 3 }$ + $\mathrm { B } _ { 2 }$ ? 2 $\mathrm { DBA } _ { 4 }$ + 2 $\mathrm { CA } _ { 2 }$ 
B) 2 $\mathrm { AB } _ { 2 }$ + 2 $\mathrm { CDA } _ { 3 }$ + $\mathrm { B } _ { 2 }$ ? 2 $\mathrm { C } _ { 2 }$ $\mathrm { A } _ { 4 }$ + 2 DBA 
C) 2 $\mathrm { AB } _ { 2 }$ + 2 $\mathrm { CDA } _ { 3 }$ + $\mathrm { A } _ { 2 }$ ? 2 $\mathrm { DBA } _ { 4 }$ + 2 $\mathrm { CA } _ { 2 }$ 
D) 2 $\mathrm { BA } _ { 2 }$ + 2 $\mathrm { CDA } _ { 3 }$ + $\mathrm { A } _ { 2 }$ ? 2 $\mathrm { DBA } _ { 4 }$ + 2 $\mathrm { CA } _ { 2 }$ 
A) 2 $\mathrm { AB } _ { 2 }$ + 2 $\mathrm { DCB } _ { 3 }$ + $\mathrm { B } _ { 2 }$ ? 2 $\mathrm { DBA } _ { 4 }$ + 2 $\mathrm { CA } _ { 2 }$ 
B) 2 $\mathrm { AB } _ { 2 }$ + 2 $\mathrm { CDA } _ { 3 }$ + $\mathrm { B } _ { 2 }$ ? 2 $\mathrm { C } _ { 2 }$ $\mathrm { A } _ { 4 }$ + 2 DBA 
C) 2 $\mathrm { AB } _ { 2 }$ + 2 $\mathrm { CDA } _ { 3 }$ + $\mathrm { A } _ { 2 }$ ? 2 $\mathrm { DBA } _ { 4 }$ + 2 $\mathrm { CA } _ { 2 }$ 
D) 2 $\mathrm { BA } _ { 2 }$ + 2 $\mathrm { CDA } _ { 3 }$ + $\mathrm { A } _ { 2 }$ ? 2 $\mathrm { DBA } _ { 4 }$ + 2 $\mathrm { CA } _ { 2 }$

Question 10

How many grams of water, $\mathrm { H } _ { 2 }$ O,and propene, $\mathrm { C } _ { 3 }$ $\mathrm { H } _ { 6 }$ ,can be formed from the reaction of 6.0 g of 2-propanol, $\mathrm { C } _ { 3 }$ $\mathrm { H } _ { 8 }$ O? $\mathrm { C } _ { 3 }$ $\mathrm { H } _ { 8 }$ O ? $\mathrm { C } _ { 3 }$ $\mathrm { H } _ { 6 }$ + $\mathrm { H } _ { 2 }$ 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 11

What can you deduce about the activation energy of a reaction that takes billions of years to go to completion? How about a reaction that takes only fractions of a second?

Accepted Answer

A) The activation energy of both these reactions must be very low. 
B) The activation energy of both these reactions must be very high. 
C) The slow reaction must have a high activation energy while the fast reaction must have a low activation energy. 
D) The slow reaction must have a low activation energy while the fast reaction must have a high activation energy. 
A) The activation energy of both these reactions must be very low. 
B) The activation energy of both these reactions must be very high. 
C) The slow reaction must have a high activation energy while the fast reaction must have a low activation energy. 
D) The slow reaction must have a low activation energy while the fast reaction must have a high activation energy.

Question 12

Are the chemical reactions that take place in a disposable battery exothermic or endothermic? Is the reaction going on in a rechargeable battery while it is recharging exothermic or endothermic?

Accepted Answer

A) An operating disposable battery is driven by endothermic reaction,while a recharging rechargeable battery is also driven by endothermic reactions. 
B) An operating disposable battery is driven by exothermic reaction,while a recharging rechargeable battery is driven by endothermic reactions. 
C) An operating disposable battery is driven by endothermic reaction,while a recharging rechargeable battery is driven by exothermic reactions. 
D) An operating disposable battery is driven by exothermic reaction,while a recharging rechargeable battery is also driven by exothermic reactions. 
A) An operating disposable battery is driven by endothermic reaction,while a recharging rechargeable battery is also driven by endothermic reactions. 
B) An operating disposable battery is driven by exothermic reaction,while a recharging rechargeable battery is driven by endothermic reactions. 
C) An operating disposable battery is driven by endothermic reaction,while a recharging rechargeable battery is driven by exothermic reactions. 
D) An operating disposable battery is driven by exothermic reaction,while a recharging rechargeable battery is also driven by exothermic reactions.

Question 13

Some reactions are more sluggish than others.To speed up these reactions and save energy a(n)________ is sometimes added.

Accepted Answer

A) catalyst 
B) activator 
C) heat source 
D) exotherm 
E) reaction profile 
A) catalyst 
B) activator 
C) heat source 
D) exotherm 
E) reaction profile

Question 14

According to the following balanced chemical equation,if you want to generate two moles of H2O,how many molecules of O2 do you need? 2 H2 + O2 → 2 H2O

Accepted Answer

A) 1 
B) 2 
C) 1/2 
D) 4 
E) 6.022 × 1023 
A) 1 
B) 2 
C) 1/2 
D) 4 
E) 6.022 × 1023

Question 15

How is ozone produced in the upper atmosphere?

Accepted Answer

A) It forms by reaction of oxygen molecules with UV light. 
B) It forms by nuclear decomposition of oxygen. 
C) It diffuses from the lower atmosphere. 
D) It forms by the reaction of nitric dioxide and oxygen. 
E) all of the above 
A) It forms by reaction of oxygen molecules with UV light. 
B) It forms by nuclear decomposition of oxygen. 
C) It diffuses from the lower atmosphere. 
D) It forms by the reaction of nitric dioxide and oxygen. 
E) all of the above

Question 16

Balance the following equation. ________ NO → ________ N2O + ________ NO2

Accepted Answer

A) 3,1,1 
B) 3,0,0 
C) 4,4,8 
D) 1,2,4 
E) 6,2,1 
A) 3,1,1 
B) 3,0,0 
C) 4,4,8 
D) 1,2,4 
E) 6,2,1

Question 17

If the relative mass of a hydrogen atom is 1/4 that of a helium atom,how many helium atoms would you need to equal the mass of 200 hydrogen atoms?

Accepted Answer

A) 50 
B) 200 
C) 800 
D) 4 
E) 100 
A) 50 
B) 200 
C) 800 
D) 4 
E) 100

Question 18

Two amu equals how many grams?

Accepted Answer

A) 2 grams 
B) 1.661 × $10 ^ { - 24 }$ grams 
C) 3.322 × $10 ^ { - 24 }$ grams 
D) 1.204 × $10 ^ { - 22 }$ 
A) 2 grams 
B) 1.661 × $10 ^ { - 24 }$ grams 
C) 3.322 × $10 ^ { - 24 }$ grams 
D) 1.204 × $10 ^ { - 22 }$

Question 19

Why does a glowing splint of wood burn only slowly in air,but rapidly in a burst of flames when placed in pure oxygen?

Accepted Answer

A) There is a greater number of collisions between the wood and oxygen molecules. 
B) Oxygen is a flammable gas. 
C) Pure oxygen is able to absorb carbon dioxide at a faster rate. 
D) A glowing wood splint is actually extinguished within pure oxygen because there's no room for the smoke to expand. 
A) There is a greater number of collisions between the wood and oxygen molecules. 
B) Oxygen is a flammable gas. 
C) Pure oxygen is able to absorb carbon dioxide at a faster rate. 
D) A glowing wood splint is actually extinguished within pure oxygen because there's no room for the smoke to expand.

Question 20

Why does iodine, $\mathrm { I } _ { 2 }$ (s),spontaneously sublime at room temperature?

Accepted Answer

A) The contact of iodine, $\mathrm { I } _ { 2 }$ (s),with the water vapor in the air causes the sublimation process. 
B) Iodine, $\mathrm { I } _ { 2 }$ (s),pulls $\mathrm { O } _ { 2 }$ from the air as it self-oxidizes under sublimation to $\mathrm { I } _ { 2 }$ (g). 
C) There is an increase in entropy as solid iodine, $\mathrm { I } _ { 2 }$ (s),sublimes into iodine vapor, $\mathrm { I } _ { 2 }$ (g),because in the gaseous phase energy is more readily dispersed. 
D) The reaction of $\mathrm { I } _ { 2 }$ (s)subliming to $\mathrm { I } _ { 2 }$ 
A) The contact of iodine, $\mathrm { I } _ { 2 }$ (s),with the water vapor in the air causes the sublimation process. 
B) Iodine, $\mathrm { I } _ { 2 }$ (s),pulls $\mathrm { O } _ { 2 }$ from the air as it self-oxidizes under sublimation to $\mathrm { I } _ { 2 }$ (g). 
C) There is an increase in entropy as solid iodine, $\mathrm { I } _ { 2 }$ (s),sublimes into iodine vapor, $\mathrm { I } _ { 2 }$ (g),because in the gaseous phase energy is more readily dispersed. 
D) The reaction of $\mathrm { I } _ { 2 }$ (s)subliming to $\mathrm { I } _ { 2 }$

Exam 17: How Chemicals React

Which of the following statements about catalysts is NOT true?

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

What is the main difficulty in trying to eliminate chlorinated fluorocarbons from the atmosphere?

Given the following generic chemical reaction,which is the product? X → Y

-How many diatomic molecules are represented in the illustration above?

Which is higher in an endothermic reaction: the potential energy of the reactants or the potential energy of the products?

If the relative mass of a pingpong ball is 1/20 that of a golf ball,how many pingpong balls would you need to equal the mass of two golf balls?

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

-Which equation best describes the reaction represented in the illustration above?

What can you deduce about the activation energy of a reaction that takes billions of years to go to completion? How about a reaction that takes only fractions of a second?

Are the chemical reactions that take place in a disposable battery exothermic or endothermic? Is the reaction going on in a rechargeable battery while it is recharging exothermic or endothermic?

Some reactions are more sluggish than others.To speed up these reactions and save energy a(n)________ is sometimes added.

According to the following balanced chemical equation,if you want to generate two moles of H2O,how many molecules of O2 do you need? 2 H2 + O2 → 2 H2O

How is ozone produced in the upper atmosphere?

Balance the following equation. ________ NO → ________ N2O + ________ NO2

If the relative mass of a hydrogen atom is 1/4 that of a helium atom,how many helium atoms would you need to equal the mass of 200 hydrogen atoms?

Two amu equals how many grams?

Why does a glowing splint of wood burn only slowly in air,but rapidly in a burst of flames when placed in pure oxygen?

Why does iodine, I2\mathrm { I } _ { 2 }I2​ (s),spontaneously sublime at room temperature?

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

Mixtures

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Time - Reading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: The Nature of Science

Filters

According to the following balanced chemical equation,if you want to generate two moles of H₂O,how many molecules of O₂ do you need? 2 H₂ + O₂ → 2 H₂O

Balance the following equation. NO → N₂O + NO₂

Why does iodine, $\mathrm { I } _ { 2 }$ (s),spontaneously sublime at room temperature?