Question 1

Which of the following is the equilibrium constant expression for the reaction? 2NO(g)+ O2(g)? 2NO2(g)

Accepted Answer

A) Keq = $\frac{\left[\mathrm{NO}_{2}\right]}{\left[\mathrm{NO}^{2}\left[\mathrm{O}_{2}\right]\right.}$ 
B) Keq = $\frac { \left[ \mathrm { NO } _ { 2 } \right] ^ { 2 } } { \left[ \mathrm { NO } ^ { 2 } \left[ \mathrm { O } _ { 2 } \right] \right. }$ 
C) Keq = $\frac { \left[ \mathrm { NO } _ { 2 } \right] ^ { 2 } } { [ \mathrm { NO } ] ^ { 2 } + \left[ \mathrm { O } _ { 2 } \right] }$ 
D) Keq = $\frac { 2 \left[ \mathrm { NO } _ { 2 } \right] } { 2 [ \mathrm { NO } ] + \left[ \mathrm { O } _ { 2 } \right] }$ 
E) None of the choices are correct. 
A) Keq = $\frac{\left[\mathrm{NO}_{2}\right]}{\left[\mathrm{NO}^{2}\left[\mathrm{O}_{2}\right]\right.}$ 
B) Keq = $\frac { \left[ \mathrm { NO } _ { 2 } \right] ^ { 2 } } { \left[ \mathrm { NO } ^ { 2 } \left[ \mathrm { O } _ { 2 } \right] \right. }$ 
C) Keq = $\frac { \left[ \mathrm { NO } _ { 2 } \right] ^ { 2 } } { [ \mathrm { NO } ] ^ { 2 } + \left[ \mathrm { O } _ { 2 } \right] }$ 
D) Keq = $\frac { 2 \left[ \mathrm { NO } _ { 2 } \right] } { 2 [ \mathrm { NO } ] + \left[ \mathrm { O } _ { 2 } \right] }$ 
E) None of the choices are correct. B

Question 2

Ethylene glycol has a specific heat of 0.578 cal/(g•°C).If 23.2 g of ethylene glycol absorbs 75.6 cal of heat energy,what will the temperature increase be?

Accepted Answer

A) 0.177°C 
B) 1.88°C 
C) 5.64°C 
D) 1.01 × 103°C 
E) 3.03 × 103 °C 
A) 0.177°C 
B) 1.88°C 
C) 5.64°C 
D) 1.01 × 103°C 
E) 3.03 × 103 °C C

Question 3

A carbohydrate sample weighing 0.235 g was found to have a fuel value of 3.84 kJ.What is the fuel value of one gram of this carbohydrate,in nutritional Calories? [1 cal = 4.18 J]

Accepted Answer

A) 3,910 Cal 
B) 0.535 Cal 
C) 16.3 Cal 
D) 643 Cal 
E) 3.91 Cal 
A) 3,910 Cal 
B) 0.535 Cal 
C) 16.3 Cal 
D) 643 Cal 
E) 3.91 Cal E

Question 4

Thermodynamics is best described as which of the following?

Accepted Answer

A) the study of the rates at which reactions take place 
B) the field of chemistry that determines the mechanisms of reactions 
C) the study of LeChatelier's Principle 
D) the study of energy,work,and heat 
E) the study of the mass relationships in chemical reactions 
A) the study of the rates at which reactions take place 
B) the field of chemistry that determines the mechanisms of reactions 
C) the study of LeChatelier's Principle 
D) the study of energy,work,and heat 
E) the study of the mass relationships in chemical reactions

Question 5

Which statement concerning energy changes in chemical reactions is FALSE?

Accepted Answer

A) The breaking of bonds requires energy,and the formation of bonds releases energy. 
B) Activation energy is the minimum amount of energy required to initiate a chemical reaction. 
C) A reaction is exothermic if the products have a lower energy than the reactants. 
D) A reaction is endothermic if the reactants have a lower energy than the products. 
E) The overall change in enthalpy (∆H)for a reaction is determined by the difference in energy between the products and the activated complex. 
A) The breaking of bonds requires energy,and the formation of bonds releases energy. 
B) Activation energy is the minimum amount of energy required to initiate a chemical reaction. 
C) A reaction is exothermic if the products have a lower energy than the reactants. 
D) A reaction is endothermic if the reactants have a lower energy than the products. 
E) The overall change in enthalpy (∆H)for a reaction is determined by the difference in energy between the products and the activated complex.

Question 6

Consider the reversible reaction: N2(g)+ 3H2(g)? 2NH3(g) What is the correct expression for the equilibrium constant,Keq,for this reaction?

Accepted Answer

A)  $\frac { \left[ 2 \mathrm { NH } _ { 3 } \right] } { \left[ \mathrm { N } _ { 2 } \right] \left[ 3 \mathrm { H } _ { 2 } \right] }$ 
B)  $\frac { 2 \left[ \mathrm { NH } _ { 3 } \right] } { \left[ \mathrm { N } _ { 2 } \right] 3 \left[ \mathrm { H } _ { 2 } \right] }$ 
C)  $\frac { \left[ \mathrm { NH } _ { 3 } \right] ^ { 2 } } { \left[ \mathrm {~N} _ { 2 } \right] \left[ \mathrm { H } _ { 2 } \right] ^ { 3 } }$ 
D)  $\frac { \left[ \mathrm { N } _ { 2 } \right] \left[ \mathrm { H } _ { 2 } \right] ^ { 3 } } { \left[ \mathrm { NH } _ { 3 } \right] ^ { 2 } }$ 
E)  $\frac { \left[ \mathrm { N } _ { 2 } \right] 3 \left[ \mathrm { H } _ { 2 } \right] } { 2 \left[ \mathrm { NH } _ { 3 } \right] }$ 
A)  $\frac { \left[ 2 \mathrm { NH } _ { 3 } \right] } { \left[ \mathrm { N } _ { 2 } \right] \left[ 3 \mathrm { H } _ { 2 } \right] }$ 
B)  $\frac { 2 \left[ \mathrm { NH } _ { 3 } \right] } { \left[ \mathrm { N } _ { 2 } \right] 3 \left[ \mathrm { H } _ { 2 } \right] }$ 
C)  $\frac { \left[ \mathrm { NH } _ { 3 } \right] ^ { 2 } } { \left[ \mathrm {~N} _ { 2 } \right] \left[ \mathrm { H } _ { 2 } \right] ^ { 3 } }$ 
D)  $\frac { \left[ \mathrm { N } _ { 2 } \right] \left[ \mathrm { H } _ { 2 } \right] ^ { 3 } } { \left[ \mathrm { NH } _ { 3 } \right] ^ { 2 } }$ 
E)  $\frac { \left[ \mathrm { N } _ { 2 } \right] 3 \left[ \mathrm { H } _ { 2 } \right] } { 2 \left[ \mathrm { NH } _ { 3 } \right] }$

Question 7

In kinetics,the order of a reaction

Accepted Answer

A) is the inverse of the entropy of the system. 
B) must be measured experimentally. 
C) can be deduced from the balanced equation for the reaction. 
D) depends on the rate constant. 
E) depends on the concentrations of reactants. 
A) is the inverse of the entropy of the system. 
B) must be measured experimentally. 
C) can be deduced from the balanced equation for the reaction. 
D) depends on the rate constant. 
E) depends on the concentrations of reactants.

Question 8

A collision between reactant molecules that produces one or more product molecules is called an effective collision.

Accepted Answer

A) True 
 B)False

Question 9

Exothermic reactions are always spontaneous.

Accepted Answer

A) True 
 B)False

Question 10

Reactants and products that are aqueous solutions do not appear in the equilibrium constant expression.

Accepted Answer

A) True 
 B)False

Question 11

According to the second law of thermodynamics,a system and its surroundings spontaneously tend toward increasing order.

Accepted Answer

A) True 
 B)False

Question 12

The order of a reaction with respect to any reactant is shown in the rate equation.

Accepted Answer

A) True 
 B)False

Question 13

Consider the decomposition of calcium carbonate shown below.Which of the following statements correctly describes this reaction as it occurs in a test tube? CaCO3(s)+ 42.5 kcal → CaO(s)+ CO2(g)

Accepted Answer

A) The test tube would feel warm,since the reaction would absorb heat from the surroundings. 
B) The test tube would feel cold,since the reaction would absorb heat from the surroundings. 
C) The test tube would feel cold,since the reaction would release heat to the surroundings. 
D) The test tube would feel warm,since the reaction would release heat to the surroundings. 
E) It is impossible to predict without actually performing the experiment. 
A) The test tube would feel warm,since the reaction would absorb heat from the surroundings. 
B) The test tube would feel cold,since the reaction would absorb heat from the surroundings. 
C) The test tube would feel cold,since the reaction would release heat to the surroundings. 
D) The test tube would feel warm,since the reaction would release heat to the surroundings. 
E) It is impossible to predict without actually performing the experiment.

Question 14

A candy sample is completely combusted in a bomb calorimeter.The calorimeter contains 982 g of water,and the measured temperature increase is 2.62°C.What is the fuel value of the candy sample in nutritional Calories? [SHw = 1.00 cal/(g•°C)]

Accepted Answer

A) 2573 Cal 
B) 2570 Cal 
C) 2.57 Cal 
D) 0.00267 Cal 
E) 2.67 × 10−6 Cal 
A) 2573 Cal 
B) 2570 Cal 
C) 2.57 Cal 
D) 0.00267 Cal 
E) 2.67 × 10−6 Cal

Question 15

Which one of the following,if changed,would change the value of the equilibrium constant,Keq,of a reaction?

Accepted Answer

A) concentration of reactants 
B) concentration of the products 
C) temperature 
D) catalyst 
E) size of reaction vessel 
A) concentration of reactants 
B) concentration of the products 
C) temperature 
D) catalyst 
E) size of reaction vessel

Question 16

For the reaction A(g)→ 2B(g),Keq = 4.5 × 105.Which statement is TRUE for the system at equilibrium?

Accepted Answer

A) [A] >> [B] 
B) There is twice as much B as there is A in the reaction vessel. 
C) There is more than 100 times more B than there is A in the reaction vessel. 
D) There is twice as much A as there is B in the reaction vessel. 
E) Changing the temperature will have no affect on the equilibrium. 
A) [A] >> [B] 
B) There is twice as much B as there is A in the reaction vessel. 
C) There is more than 100 times more B than there is A in the reaction vessel. 
D) There is twice as much A as there is B in the reaction vessel. 
E) Changing the temperature will have no affect on the equilibrium.

Question 17

Changing the temperature alters the value of the equilibrium constant for a reaction.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following is a TRUE statement concerning the specific heat of a substance?

Accepted Answer

A) Specific heat is the amount of heat required to raise one gram of a substance by one degree Celsius. 
B) Specific heat is 1.00 cal for all substances. 
C) Specific heat is the change in the temperature of a substance as it absorbs heat. 
D) Specific heat is the amount of heat required to raise one mole of a substance by ten degrees. 
E) Specific heat is the heat given off in a chemical reaction. 
A) Specific heat is the amount of heat required to raise one gram of a substance by one degree Celsius. 
B) Specific heat is 1.00 cal for all substances. 
C) Specific heat is the change in the temperature of a substance as it absorbs heat. 
D) Specific heat is the amount of heat required to raise one mole of a substance by ten degrees. 
E) Specific heat is the heat given off in a chemical reaction.

Question 19

Which term describes the measure of the randomness or disorder of a chemical system?

Accepted Answer

A) energy 
B) calorimetry 
C) entropy 
D) enthalpy 
E) free energy 
A) energy 
B) calorimetry 
C) entropy 
D) enthalpy 
E) free energy

Question 20

A reaction that leads to a decrease in the enthalpy of the system is always spontaneous.

Accepted Answer

A) True 
 B)False

Exam 7: Energy,rate and Equilibrium

Which of the following is the equilibrium constant expression for the reaction? 2NO(g)+ O2(g)? 2NO2(g)

Ethylene glycol has a specific heat of 0.578 cal/(g•°C).If 23.2 g of ethylene glycol absorbs 75.6 cal of heat energy,what will the temperature increase be?

A carbohydrate sample weighing 0.235 g was found to have a fuel value of 3.84 kJ.What is the fuel value of one gram of this carbohydrate,in nutritional Calories? [1 cal = 4.18 J]

Thermodynamics is best described as which of the following?

Which statement concerning energy changes in chemical reactions is FALSE?

Consider the reversible reaction: N2(g)+ 3H2(g)? 2NH3(g) What is the correct expression for the equilibrium constant,Keq,for this reaction?

In kinetics,the order of a reaction

A collision between reactant molecules that produces one or more product molecules is called an effective collision.

Exothermic reactions are always spontaneous.

Reactants and products that are aqueous solutions do not appear in the equilibrium constant expression.

According to the second law of thermodynamics,a system and its surroundings spontaneously tend toward increasing order.

The order of a reaction with respect to any reactant is shown in the rate equation.

Consider the decomposition of calcium carbonate shown below.Which of the following statements correctly describes this reaction as it occurs in a test tube? CaCO3(s)+ 42.5 kcal → CaO(s)+ CO2(g)

A candy sample is completely combusted in a bomb calorimeter.The calorimeter contains 982 g of water,and the measured temperature increase is 2.62°C.What is the fuel value of the candy sample in nutritional Calories? [SHw = 1.00 cal/(g•°C)]

Which one of the following,if changed,would change the value of the equilibrium constant,Keq,of a reaction?

For the reaction A(g)→ 2B(g),Keq = 4.5 × 105.Which statement is TRUE for the system at equilibrium?

Changing the temperature alters the value of the equilibrium constant for a reaction.

Which of the following is a TRUE statement concerning the specific heat of a substance?

Which term describes the measure of the randomness or disorder of a chemical system?

A reaction that leads to a decrease in the enthalpy of the system is always spontaneous.

Chemistry - Methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

Calculations, chemical Changes, and the Chemical Equation

States of Matter: Gases, liquids, and Solids

Solutions

Acids and Bases

The Nucleus, radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry

The Unsaturated Hydrocarbons: Alkenes, alkynes, and Aromatics

Alcohols, phenols, thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

Filters

Which of the following is the equilibrium constant expression for the reaction? 2NO(g)+ O₂(g)? 2NO₂(g)

Consider the reversible reaction: N₂(g)+ 3H₂(g)? 2NH₃(g) What is the correct expression for the equilibrium constant,Keq,for this reaction?

Consider the decomposition of calcium carbonate shown below.Which of the following statements correctly describes this reaction as it occurs in a test tube? CaCO₃(s)+ 42.5 kcal → CaO(s)+ CO₂(g)

For the reaction A(g)→ 2B(g),K_eq = 4.5 × 10⁵.Which statement is TRUE for the system at equilibrium?