Question 1

Which of the following energy quantities is equivalent to 578 J?

Accepted Answer

A) 5.78 × 105 kJ 
B) 138 kcal 
C) 0.138 kcal 
D) 1.38 × 105 kcal 
A) 5.78 × 105 kJ 
B) 138 kcal 
C) 0.138 kcal 
D) 1.38 × 105 kcal

Question 2

Catalysts accelerate a reaction by ________.

Accepted Answer

A) lowering the enthalpy of the reaction 
B) lowering the energy of activation 
C) raising the enthalpy of the reaction 
D) raising the energy of activation 
A) lowering the enthalpy of the reaction 
B) lowering the energy of activation 
C) raising the enthalpy of the reaction 
D) raising the energy of activation

Question 3

The rate of a chemical reaction increases with an increase in the concentration of one or more reactants. This is best explained by which statement?

Accepted Answer

A) The higher concentration of reactants increases the potential energy of the molecules. 
B) The higher concentration of reactants increases the activation energy of the reaction. 
C) The higher concentration of reactants increases the temperature of the molecules. 
D) The higher concentration of reactants increases the frequency of collisions between molecules. 
A) The higher concentration of reactants increases the potential energy of the molecules. 
B) The higher concentration of reactants increases the activation energy of the reaction. 
C) The higher concentration of reactants increases the temperature of the molecules. 
D) The higher concentration of reactants increases the frequency of collisions between molecules.

Question 4

Kinetic energy is the energy associated with movement; potential energy is the energy inherent in an object due to its position or composition.

Accepted Answer

A) True 
 B)False

Question 5

Which term correctly describes a reaction in which the energy of the products is higher than the energy of the reactants?

Accepted Answer

A) Oxidation-reduction 
B) Endothermic 
C) Exothermic 
D) Combustion 
A) Oxidation-reduction 
B) Endothermic 
C) Exothermic 
D) Combustion

Question 6

Which bond is the strongest?

Accepted Answer

A) H-Br 
B) H-Cl 
C) H-F 
D) H-I 
A) H-Br 
B) H-Cl 
C) H-F 
D) H-I

Question 7

Walking at a brisk pace burns off about 280 Cal/h. How long would you have to walk to burn off the Calories obtained from eating a candy bar that contained 3 g of protein,12 g of fat,and 28 g of carbohydrates?

Accepted Answer

A) 55 minutes 
B) 230 minutes 
C) 50 minutes 
D) 210 minutes 
A) 55 minutes 
B) 230 minutes 
C) 50 minutes 
D) 210 minutes

Question 8

Consider the following reversible reaction at equilibrium: 2 NO(g)+ O2(g)   2 NO2(g). If oxygen gas is added to the reaction vessel,the equilibrium will shift to the left.

Accepted Answer

A) True 
 B)False

Question 9

What is the gas phase chemical reaction that corresponds to the equilibrium constant expression shown below?

Accepted Answer

A) 2 A + 4 B   2 C 
B) A + B   C 
C) 2 C   2 A + 4 B 
D) 2 C   4 A + 2 B 
E) 4 A + 2 B   2 C 
A) 2 A + 4 B   2 C 
B) A + B   C 
C) 2 C   2 A + 4 B 
D) 2 C   4 A + 2 B 
E) 4 A + 2 B   2 C

Question 10

Consider the reaction,C2H4(g)+ H2(g)→ C2H6(g),where ΔH = -137 kJ. How many kilojoules are released when 3.5 mol of C2H4 reacts?

Accepted Answer

A) 137 kJ are released 
B) 570 kJ are released 
C) 480 kJ are released 
D) 2.0 × 103 kJ are released 
A) 137 kJ are released 
B) 570 kJ are released 
C) 480 kJ are released 
D) 2.0 × 103 kJ are released

Question 11

An enzyme contains a region called its ________ that binds a reactant,which then undergoes a very specific reaction with an enhanced rate.

Accepted Answer

The answer of An enzyme contains a region called its...

Question 12

Chemical reactions are considered favorable if the products have a higher energy than the reactants.

Accepted Answer

A) True 
 B)False

Question 13

Consider the reaction: PCl3(g)+ Cl2(g)   PCl5(g). If [PCl3] = 0.78 M,[Cl2] = 0.44 M,and [PCl5] = 0.88 at equilibrium,what is the value of K?

Accepted Answer

A) 0.39 
B) 1.4 
C) 2.6 
D) 0.72 
A) 0.39 
B) 1.4 
C) 2.6 
D) 0.72

Question 14

The larger the K for a reaction,the faster the reaction.

Accepted Answer

A) True 
 B)False

Question 15

Consider the following reversible reaction at equilibrium: CO(g)+ Cl2(g)   COCl2(g). If chlorine gas is added to the reaction vessel,the concentration of carbon monoxide will decrease.

Accepted Answer

A) True 
 B)False

Question 16

The expression for the equilibrium constant,K,for the general reaction: a A + b B   c C + d D is   .

Accepted Answer

A) True 
 B)False

Question 17

Consider the combustion reaction of propane: C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g),where ΔH = -531 kcal. If 6.70 × 104 kcal of energy is released in the reaction,how many grams of oxygen were consumed?

Accepted Answer

A) 63.1 g of O2 
B) 2.02 × 104 g of O2 
C) 12.6 g of O2 
D) 404 g of O2 
A) 63.1 g of O2 
B) 2.02 × 104 g of O2 
C) 12.6 g of O2 
D) 404 g of O2

Question 18

In an ________ reaction,the products are lower in energy than the reactants.

Accepted Answer

The answer of In an ________ reaction,the products are lower...

Question 19

In the energy diagram shown below,the ΔH of the reaction is labeled by D.

Accepted Answer

A) True 
 B)False

Question 20

Consider the reaction: C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g),where ΔH = -531 kcal/mol. How much heat is released when 3.40 × 1020 molecules of C3H8(g)is burned?

Accepted Answer

A) 3.33 kcal 
B) 0.300 kcal 
C) 6.40 × 1017 kcal 
D) 1.50 kcal 
A) 3.33 kcal 
B) 0.300 kcal 
C) 6.40 × 1017 kcal 
D) 1.50 kcal

Exam 6: Energy Changes,reaction Rates,and Equilibrium

Which of the following energy quantities is equivalent to 578 J?

Catalysts accelerate a reaction by ________.

The rate of a chemical reaction increases with an increase in the concentration of one or more reactants. This is best explained by which statement?

Kinetic energy is the energy associated with movement; potential energy is the energy inherent in an object due to its position or composition.

Which term correctly describes a reaction in which the energy of the products is higher than the energy of the reactants?

Which bond is the strongest?

Walking at a brisk pace burns off about 280 Cal/h. How long would you have to walk to burn off the Calories obtained from eating a candy bar that contained 3 g of protein,12 g of fat,and 28 g of carbohydrates?

Consider the following reversible reaction at equilibrium: 2 NO(g)+ O2(g) 2 NO2(g). If oxygen gas is added to the reaction vessel,the equilibrium will shift to the left.

What is the gas phase chemical reaction that corresponds to the equilibrium constant expression shown below?

Consider the reaction,C2H4(g)+ H2(g)→ C2H6(g),where ΔH = -137 kJ. How many kilojoules are released when 3.5 mol of C2H4 reacts?

An enzyme contains a region called its ________ that binds a reactant,which then undergoes a very specific reaction with an enhanced rate.

Chemical reactions are considered favorable if the products have a higher energy than the reactants.

Consider the reaction: PCl3(g)+ Cl2(g) PCl5(g). If [PCl3] = 0.78 M,[Cl2] = 0.44 M,and [PCl5] = 0.88 at equilibrium,what is the value of K?

The larger the K for a reaction,the faster the reaction.

Consider the following reversible reaction at equilibrium: CO(g)+ Cl2(g) COCl2(g). If chlorine gas is added to the reaction vessel,the concentration of carbon monoxide will decrease.

The expression for the equilibrium constant,K,for the general reaction: a A + b B c C + d D is .

Consider the combustion reaction of propane: C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g),where ΔH = -531 kcal. If 6.70 × 104 kcal of energy is released in the reaction,how many grams of oxygen were consumed?

In an ________ reaction,the products are lower in energy than the reactants.

In the energy diagram shown below,the ΔH of the reaction is labeled by D.

Consider the reaction: C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g),where ΔH = -531 kcal/mol. How much heat is released when 3.40 × 1020 molecules of C3H8(g)is burned?

Matter and Measurement

Atoms and the Periodic Table

Ionic Compounds

Covalent Compounds

Chemical Reactions

Gases,liquids,and Solids

Solutions

Acids and Bases

Nuclear Chemistry

Introduction to Organic Molecules and Functional Groups

Alkanes

Unsaturated Hydrocarbons

Organic Compounds That Contain Oxygen,halogen,or Sulfur

The Three-Dimensional Shape of Molecules

Aldehydes and Ketones

Carboxylic Acids,esters,and Amides

Amines and Neurotransmitters

Lipids

Carbohydrates

Amino Acids,proteins,and Enzymes

Nucleic Acids and Protein Synthesis

Metabolism and Energy Production

Carbohydrate,lipid,and Protein Metabolism

Filters

Consider the following reversible reaction at equilibrium: 2 NO(g)+ O₂(g) 2 NO₂(g). If oxygen gas is added to the reaction vessel,the equilibrium will shift to the left.

Consider the reaction,C₂H₄(g)+ H₂(g)→ C₂H₆(g),where ΔH = -137 kJ. How many kilojoules are released when 3.5 mol of C₂H₄ reacts?

Consider the reaction: PCl₃(g)+ Cl₂(g) PCl₅(g). If [PCl₃] = 0.78 M,[Cl₂] = 0.44 M,and [PCl₅] = 0.88 at equilibrium,what is the value of K?

Consider the following reversible reaction at equilibrium: CO(g)+ Cl₂(g) COCl₂(g). If chlorine gas is added to the reaction vessel,the concentration of carbon monoxide will decrease.

Consider the combustion reaction of propane: C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)+ 4 H₂O(g),where ΔH = -531 kcal. If 6.70 × 10⁴ kcal of energy is released in the reaction,how many grams of oxygen were consumed?

Consider the reaction: C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)+ 4 H₂O(g),where ΔH = -531 kcal/mol. How much heat is released when 3.40 × 10²⁰ molecules of C₃H₈(g)is burned?