Chem II Exam 2 UPDATED QUESTIONS
AND CORRECT ANSWERS
W
hich of the following statements are always true for a reaction at equilibrium?
I. The rate of the forward and reverse reactions are equal.
II. The concentrations of the reactants and the products remain constant.
III. The amount of reactants is equal to the amount of products. - CORRECT
ANSWER I. The rate of the forward and reverse reactions are equal.
II. The concentrations of the reactants and the products remain constant.
Consider the following energy diagram and determine which of the following statements is
true. - CORRECT ANSWER B) K = k_forward/k_reverse < 1
K= - CORRECT ANSWER [products]/[reactants]
for concentration of reactants and products in k, exclude - CORRECT ANSWER solids
& liquids
Kc = - CORRECT ANSWER Kfwd / Krvs
______ & _____ have no effect on concentration - CORRECT ANSWER solids &
liquids
If Kc is big (10^10), then _________ >> _________ - CORRECT
ANSWER [products] >> [reactants]
If Kc is small (10^-10), then _________ << _____________ - CORRECT
ANSWER [products] << [reactants]
, equilibrium (does/does not) depend on starting conc. WHY? - CORRECT
ANSWER DOES NOT - bc will always eventually find equilibrium
How to relate Kp and Kc - CORRECT ANSWER Kp = (Kc)(RT)^(delta n)
if delta n = 0 - CORRECT ANSWER Kp = Kc
At equilibrium Q= - CORRECT ANSWER Kc
for Kc at equilibrium (Q) to become smaller than Kc, numerator must ______ & denominator
must _______ - CORRECT ANSWER decrease, increase
if Q>K, - CORRECT ANSWER reaction shifts left (towards reactants
if Q=K - CORRECT ANSWER reaction is at equilibrium
if Q<K - CORRECT ANSWER reaction shifts right (needs more products, or less
reactants)
if the soln is all reactants, Q = - CORRECT ANSWER 0
if the soln is all products, Q = - CORRECT ANSWER infinity
increasing [reactants] means a shift towards ______ to reach equilibrium - CORRECT
ANSWER products
decreasing V equilibrium response - CORRECT ANSWER equilibrium shifts towards
the side that takes up less V in gas
AND CORRECT ANSWERS
W
hich of the following statements are always true for a reaction at equilibrium?
I. The rate of the forward and reverse reactions are equal.
II. The concentrations of the reactants and the products remain constant.
III. The amount of reactants is equal to the amount of products. - CORRECT
ANSWER I. The rate of the forward and reverse reactions are equal.
II. The concentrations of the reactants and the products remain constant.
Consider the following energy diagram and determine which of the following statements is
true. - CORRECT ANSWER B) K = k_forward/k_reverse < 1
K= - CORRECT ANSWER [products]/[reactants]
for concentration of reactants and products in k, exclude - CORRECT ANSWER solids
& liquids
Kc = - CORRECT ANSWER Kfwd / Krvs
______ & _____ have no effect on concentration - CORRECT ANSWER solids &
liquids
If Kc is big (10^10), then _________ >> _________ - CORRECT
ANSWER [products] >> [reactants]
If Kc is small (10^-10), then _________ << _____________ - CORRECT
ANSWER [products] << [reactants]
, equilibrium (does/does not) depend on starting conc. WHY? - CORRECT
ANSWER DOES NOT - bc will always eventually find equilibrium
How to relate Kp and Kc - CORRECT ANSWER Kp = (Kc)(RT)^(delta n)
if delta n = 0 - CORRECT ANSWER Kp = Kc
At equilibrium Q= - CORRECT ANSWER Kc
for Kc at equilibrium (Q) to become smaller than Kc, numerator must ______ & denominator
must _______ - CORRECT ANSWER decrease, increase
if Q>K, - CORRECT ANSWER reaction shifts left (towards reactants
if Q=K - CORRECT ANSWER reaction is at equilibrium
if Q<K - CORRECT ANSWER reaction shifts right (needs more products, or less
reactants)
if the soln is all reactants, Q = - CORRECT ANSWER 0
if the soln is all products, Q = - CORRECT ANSWER infinity
increasing [reactants] means a shift towards ______ to reach equilibrium - CORRECT
ANSWER products
decreasing V equilibrium response - CORRECT ANSWER equilibrium shifts towards
the side that takes up less V in gas
