Chapter 14 Notes and Questions

Which is ICE RIGHT when we talk about equilibrium? ICE is the crystal for water It's Initial (I), Change(C) and Equilibrium (E) ICE can not be used to calculate the concentrations at equilibrium All above

b. It's Initial (I), Change(C) and Equilibrium (E)

Which of the following is (are) unaffected by reversing the direction in which a chemical equation is written? A) The equilibrium concentrations B) The equilibrium constant value C) The mass action expression D) All of the above

A) The equilibrium concentrations

Consider the following reaction: CaCO3(s) ↔ CO2(g) + CaO(s) . What will happen to the system if more CaCO3 is added? A) nothing B) the amount of CaCO3 will decrease C) less CaO will be produced D) the pressure will increase E) the concentration of CO2 will decrease

A) nothing

The value of the equilibrium constant is not affected by the concentrations of A) pure solids and liquids. B) gases. C) aqueous solutions. D) all of the above.

A) pure solids and liquids.

Consider the following reaction: 2H2(g) + 2Cl2(g) ↔ 2HCl(g) + heat. What will happen to the system if the volume of the reaction vessel is decreased? A) more HCl will dissociate B) amounts of H2 and Cl2 will decrease C) less heat is produced D) all of the above

B) amounts of H2 and Cl2 will decrease

Calculate the equilibrium constant for the process A ↔ B, given the following equilibrium concentrations: [N2O4] = 0.0427 M ; [NO2] = 0.0141 M A) 6.60x10-1 B) 215 C) 0.00466 D) D) 0.3300.330

C) 0.00466

Chemical reactions take place because the molecules involved in a reaction A) break apart spontaneously, then recombine. B) exist only above a certain temperature. C) collide with each other and break bonds. D) are moving very fast.

C) collide with each other and break bonds.

If an equilibrium for a reaction is said to lie to the right then the equilibrium constant A) is a negative value. B) is a positive value less than one. C) is a positive value greater than one. D) is equal to one.

C) is a positive value greater than one.

The concentrations of pure solids are normally excluded in an equilibrium constant expression because A) these substances do not participate in the processes that are at equilibrium. B) at the time the equilibrium is established, their absolute amounts have not varied from the original amounts. C) the concentration of a pure solid remains essentially constant throughout the reaction. D) they do not play a vital role in the rate-determining step of the reaction.

C) the concentration of a pure solid remains essentially constant throughout the reaction.

Which is RIGHT about equilibrium? There is no chemical reaction exist at Chemical equilibrium There is no phase change at physical equilibrium There is no concentration change at Chemical equilibrium Equilibrium will not change with condition

There is no concentration change at Chemical equilibrium

Which one will not shift the equilibrium?a Temperature Pressure Catalyst Concentration

c. Catalyst

For this reaction A+2B arrow AB

c. Equilibrium constant Kc=kf/kr= AB/AB^2

Which is RIGHT about catalyst? does not change K does not shift the position of an equilibrium system system will reach equilibrium sooner All of them

d. All of them

Consider the following reaction: 4HCl(g) + O2(g) ↔ 2H2O(g) + 2Cl2(g) with Δ H = -114.4 kJ One way to decrease the amount of chlorine present at equilibrium is A) removing the water vapor while it is being formed. B) raising the temperature. C) adding more hydrogen chloride. D) decreasing the volume of the reaction vessel.

B) raising the temperature.

For a particular set of concentrations, if the value of Q is much greater than the value of the equilibrium constant, K, for a reaction, then A) the initial rate of the reaction will be very fast, but will slow as equilibrium is approached. B) the reaction will proceed to the right, but the rate cannot be determined from the Q or K. C) the reaction will proceed to the left, but the rate cannot be determined from the Q or K. D) the reaction will proceed to make more products if the value of K is

C) the reaction will proceed to the left, but the rate cannot be determined from the Q or K.

The reaction of hydrogen gas with nitrogen gas to produce ammonia gas is exothermic. Which of the following is true? A) Increasing the pressure of the reaction system will increase production of ammonia. B) Condensing the ammonia gas produced into liquid will increase the production of ammonia. C) Decreasing the temperature of the reaction will increase the production of ammonia. D) All of the above.

D) All of the above.

Which of the following statements is true of a catalyst? A) Its concentration stays constant throughout the reaction B) it increases the rate of a reaction C) it provides a new pathway for the reaction D) all of the above

D) all of the above

The reaction of oxygen with hemoglobin produces oxyhemoglobin, which carries oxygen to body tissues. At high altitudes the following results are seen A) the lower oxygen pressure causes the equilibrium to shift away from oxyhemoglobin. B) "altitude sickness" can occur in unacclimated individuals. C) people who live in higher altitudes develop higher levels of hemoglobin to function normally. D) all of the above.

D) all of the above.

Which is RIGHT for A+ B⇄ C+ D ? K>>1, favor reactants K>>1, Lie to the left K<<1, favor products K<<1, Lie to the left

K<<1, Lie to the left

Which is WRONG? equilibrium does not apply to reactions in which all reacting species are in the different phases Homogeneous equilibrium applies to reactions in which all reacting species are in the same phase concentration of solids and pure liquids are not included in the expression for the equilibrium constant none of them are wrong

a. equilibrium does not apply to reactions in which all reacting species are in the different phases

Which one will change the equilibrium constant? Temperature Pressure Catalyst Concentration

a. temperature

Which is WRONG about Le Châtelier's Principle? For Exothermic reaction, Increase temperature, K decreases For endothermic reaction, Increase temperature, K increases For Exothermic reaction, decrease temperature, K decreases For endothermic reaction, decrease temperature, K decreases

c. For Exothermic reaction, decrease temperature, K decreases

Which is WRONG about Le Châtelier's Principle? When Change concentration, Equilibrium Shifts, Equilibrium Constant will not change When Change pressure and volume, Equilibrium Shifts, Equilibrium Constant will not change When Change temperature, Equilibrium Shifts, Equilibrium Constant will not change When adding catalyst, Equilibrium won't Shifts, Equilibrium Constant will change

c. When Change temperature, Equilibrium Shifts, Equilibrium Constant will not change

Which is RIGHT about Equilibrium Constants? a. If a reaction can be expressed as the sum of two or more reactions, the equilibrium constant for the overall reaction is given by the product of the equilibrium constants of the individual reactions: b. for a reversible reaction: x ′ =1 c. concentrations of pure solids, pure liquids and solvents do not appear in the equilibrium constant expressions d. all above

d. all above

which statement is right about Reaction Quotient? at equilibrium, = =1 < system proceeds from right to left system proceeds from left to right is the expression at possible time, Kc is only at equilibrium

d. is the expression at possible time, Kc is only at equilibrium

The reaction N2O4(g) ↔ 2NO2(g) is endothermic. Which of the following is true? A) Decreasing the pressure drives the reaction to the right. B) Increasing the temperature drives the reaction to the right. C) Decreasing the volume drives the reaction to the left. D) All of the above.

D) All of the above.

Which is RIGHT about this reaction? N2O4 ( )⇄2NO2 ( ) ∆ °=58.0 kJ∕mol Increase temperature, K increaseDecrease temperature, K decrease Increase pressure, reaction shift to left All above

d. All of the Above

Which is right for N2o4(g)2N02(g)?

kp=(No2)^2/PN2O2

At equilibrium A) the rate constants for the forward and reverse reactions are equal. B) the reaction ends. C) all reactants have been converted to products. D) the forward and reverse rates are equal.

D) the forward and reverse rates are equal.