Question 1

In the reaction: 2 C2H6(g)+ 7 O2(g)→ 4 CO2(g)+ 6 H2O(g),increasing the concentration of C2H6(g)will ________.

Accepted Answer

A) increase the activation energy of the reaction 
B) decrease the activation energy of the reaction 
C) decrease the ΔH of the reaction 
D) increase the reaction rate 
E) decrease the reaction rate 
A) increase the activation energy of the reaction 
B) decrease the activation energy of the reaction 
C) decrease the ΔH of the reaction 
D) increase the reaction rate 
E) decrease the reaction rate D

Question 2

Which K value below is consistent with an equilibrium system in which the products are favored?

Accepted Answer

A) K = 1 
B) K = 5.2 x 104 
C) K = 3.8 x 10-6 
D) K = 0.100 
A) K = 1 
B) K = 5.2 x 104 
C) K = 3.8 x 10-6 
D) K = 0.100 B

Question 3

Consider the reversible reaction: PCl3(g)+ Cl2(g)   PCl5(g),where K = 0.5. Since K 5] must be less than 1 M.

Accepted Answer

A) True 
 B)False  False

Question 4

Which bond is the weakest?

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 5

Increasing the concentration of the reactants in a chemical reaction increases the number of collisions,and the reaction rate increases.

Accepted Answer

A) True 
 B)False

Question 6

Activation energy is the minimum amount of energy necessary for a reaction to occur.

Accepted Answer

A) True 
 B)False

Question 7

Reactions with high Ea are generally fast reactions.

Accepted Answer

A) True 
 B)False

Question 8

A reversible reaction has reached equilibrium when which condition is established?

Accepted Answer

A) the reverse reaction begins to occur 
B) the concentrations of reactants and products become equal 
C) all of the reactants have been converted into products 
D) the forward and reverse reaction rates become equal 
A) the reverse reaction begins to occur 
B) the concentrations of reactants and products become equal 
C) all of the reactants have been converted into products 
D) the forward and reverse reaction rates become equal

Question 9

An endothermic reaction is one in which energy is absorbed and ΔH is negative (-).

Accepted Answer

A) True 
 B)False

Question 10

Energy is the capacity to do work.

Accepted Answer

A) True 
 B)False

Question 11

Consider the reaction,C2H4(g)+ H2(g)→ C2H6(g),where ΔH = -137 kJ. How many kilojoules are released when 55.3 g of C2H4 reacts?

Accepted Answer

A) 137 kJ are released 
B) 270. kJ are released 
C) 1.13 × 103 kJ are released 
D) 7.58 × 103 kJ are released 
A) 137 kJ are released 
B) 270. kJ are released 
C) 1.13 × 103 kJ are released 
D) 7.58 × 103 kJ are released

Question 12

Consider the following reversible reaction at equilibrium: C­6­H12O6 (aq)+ 6 O2(g)   6 CO2(g)+ 6 H2O(l). If oxygen gas is removed from the reaction vessel,the equilibrium will shift to the right.

Accepted Answer

A) True 
 B)False

Question 13

The stronger the bond,the higher its bond dissociation energy.

Accepted Answer

A) True 
 B)False

Question 14

For an endothermic reaction at equilibrium,increasing the temperature ________.

Accepted Answer

A) does not shift the equilibrium since K is a constant 
B) increases the rate of the reverse reaction to form more reactants 
C) increases the rate of the forward reaction to form more products 
D) increases the rate of the reverse reaction to form more products 
A) does not shift the equilibrium since K is a constant 
B) increases the rate of the reverse reaction to form more reactants 
C) increases the rate of the forward reaction to form more products 
D) increases the rate of the reverse reaction to form more products

Question 15

Breaking a chemical bond requires energy.

Accepted Answer

A) True 
 B)False

Question 16

As a general rule,a reaction rate ________ for each 10 °C the temperature is raised.

Accepted Answer

The answer of As a general rule,a reaction rate ________...

Question 17

The rusting of iron is described by the reaction: 4 Fe(s)+ 3 O2(g)→ 2 Fe2O3(s). The formation of rust on an exposed piece of iron typically takes several months. Which of the following is NOT a reasonable assumption about this chemical reaction?

Accepted Answer

A) The formation of rust has a low reaction rate. 
B) The formation of rust has a low activation energy. 
C) The formation of rust would occur more slowly at higher altitudes where the concentration of oxygen is lower. 
D) The formation of rust would occur faster in the warmer summer months than in the cooler winter months. 
A) The formation of rust has a low reaction rate. 
B) The formation of rust has a low activation energy. 
C) The formation of rust would occur more slowly at higher altitudes where the concentration of oxygen is lower. 
D) The formation of rust would occur faster in the warmer summer months than in the cooler winter months.

Question 18

Exothermic reactions involve the formation of products having lower energy than the reactants.

Accepted Answer

A) True 
 B)False

Question 19

The law of conservation of energy states that ________.

Accepted Answer

A) the energy of the reactants and products in a chemical reaction are always equal 
B) all chemical reactions are reversible 
C) energy can be created,but not destroyed 
D) energy cannot be created or destroyed 
A) the energy of the reactants and products in a chemical reaction are always equal 
B) all chemical reactions are reversible 
C) energy can be created,but not destroyed 
D) energy cannot be created or destroyed

Question 20

Consider the following reversible reaction at equilibrium: CO(g)+ Cl2(g)   COCl2(g). If the pressure inside the reaction vessel is increased,the equilibrium will shift to the left.

Accepted Answer

A) True 
 B)False

Exam 6: Energy Changes,reaction Rates,and Equilibrium

In the reaction: 2 C2H6(g)+ 7 O2(g)→ 4 CO2(g)+ 6 H2O(g),increasing the concentration of C2H6(g)will ________.

Which K value below is consistent with an equilibrium system in which the products are favored?

Consider the reversible reaction: PCl3(g)+ Cl2(g) PCl5(g),where K = 0.5. Since K < 1,[PCl5] must be less than 1 M.

Which bond is the weakest?

Increasing the concentration of the reactants in a chemical reaction increases the number of collisions,and the reaction rate increases.

Activation energy is the minimum amount of energy necessary for a reaction to occur.

Reactions with high Ea are generally fast reactions.

A reversible reaction has reached equilibrium when which condition is established?

An endothermic reaction is one in which energy is absorbed and ΔH is negative (-).

Energy is the capacity to do work.

Consider the reaction,C2H4(g)+ H2(g)→ C2H6(g),where ΔH = -137 kJ. How many kilojoules are released when 55.3 g of C2H4 reacts?

Consider the following reversible reaction at equilibrium: C­6­H12O6 (aq)+ 6 O2(g) 6 CO2(g)+ 6 H2O(l). If oxygen gas is removed from the reaction vessel,the equilibrium will shift to the right.

The stronger the bond,the higher its bond dissociation energy.

For an endothermic reaction at equilibrium,increasing the temperature ________.

Breaking a chemical bond requires energy.

As a general rule,a reaction rate ________ for each 10 °C the temperature is raised.

The rusting of iron is described by the reaction: 4 Fe(s)+ 3 O2(g)→ 2 Fe2O3(s). The formation of rust on an exposed piece of iron typically takes several months. Which of the following is NOT a reasonable assumption about this chemical reaction?

Exothermic reactions involve the formation of products having lower energy than the reactants.

The law of conservation of energy states that ________.

Consider the following reversible reaction at equilibrium: CO(g)+ Cl2(g) COCl2(g). If the pressure inside the reaction vessel is increased,the equilibrium will shift to the left.

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

In the reaction: 2 C₂H₆(g)+ 7 O₂(g)→ 4 CO₂(g)+ 6 H₂O(g),increasing the concentration of C₂H₆(g)will ________.

Consider the reversible reaction: PCl₃(g)+ Cl₂(g) PCl₅(g),where K = 0.5. Since K < 1,[PCl₅] must be less than 1 M.

Reactions with high E_a are generally fast reactions.

Consider the reaction,C₂H₄(g)+ H₂(g)→ C₂H₆(g),where ΔH = -137 kJ. How many kilojoules are released when 55.3 g of C₂H₄ reacts?

Consider the following reversible reaction at equilibrium: C₆H₁₂O₆ (aq)+ 6 O₂(g) 6 CO₂(g)+ 6 H₂O(l). If oxygen gas is removed from the reaction vessel,the equilibrium will shift to the right.

The rusting of iron is described by the reaction: 4 Fe(s)+ 3 O₂(g)→ 2 Fe₂O₃(s). The formation of rust on an exposed piece of iron typically takes several months. Which of the following is NOT a reasonable assumption about this chemical reaction?

Consider the following reversible reaction at equilibrium: CO(g)+ Cl₂(g) COCl₂(g). If the pressure inside the reaction vessel is increased,the equilibrium will shift to the left.