CHEM 104 Exam 2 | Questions and
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Which statement does NOT generally apply to a chemical rxn in dynamic equilibrium?
A. The rates of the forward & reverse rxns are equal
B. The concentration of the reactants and the products are constant
C. The concentration of the reactants and the products are equal -✓✓C
The reactants and the products concentrations do not need to be the same.
What is the equilibrium constant? -✓✓The rate of equilibrium of concentration of
products raised to their stoichiometric coefficients divided by the concentrations of
reactants raised to their stoichiometric coefficients.
What can a high K value represent? [ K > 1 ] -✓✓Products dominant the reaction.
Reaction is favored to the right.
What can a low K value represent? [ K < 1 ] -✓✓Reactants dominant the reaction.
Reaction is favored to the left.
What can we tell about the chemical reaction just be looking at the K value? -✓✓The
magnitude of the equilibrium constant tells us whether a reaction favors products or
reactants at equilibrium.
What can you infer when the K constant is equal to 1? -✓✓Comparable amounts of
products and reactants are present at equilibrium.
The equilibrium constant for the reaction A (g) -> <- B (g) = 10. A reaction mixture
initially contains [A] = 1.1 M and [B] = 0.0 M. Which statement about this reaction is true
at equilibrium?
A. The equilibrium reaction mixture contains [A] = 1.0 M and [B] = 0.1 M
B. The equilibrium reaction mixture contains [A] = 0.1 M and [B] = 1.0 M
C. The equilibrium reaction mixture contains equal concentrations of A and B. -✓✓B
because K = 10
If you reverse an equilibrium reaction, what do you do to the initial K value? -✓✓Invert it.
If K = 10
K now becomes 1/10
, If you multiply the coefficients of an equilibrium reaction, what do you do to the initial K
value? -✓✓Raise the K to the same factor.
If you multiplied by 2
Raise K to the 2 (K^2)
If you add two or more reactions to obtain an overall one, what do you do to the initial
K? -✓✓Multiply the corresponding K constants by each other.
K1 x K2
In what two ways can you write equilibrium constants? -✓✓Kp and Kc
What is a Kc value? -✓✓Equilibrium constant using concentrations
What is a Kp value? -✓✓Equilibrium constant using partial pressures.
What must be true about the phases in the equilibrium reaction, to use a Kp? -✓✓All
must be in gaseous phases.
How do Kc and Kp relate? -✓✓Kp = Kc (RT) ^ Δn
If the total number of moles of gas is the same after the reaction as before than Δn,
what is true about Kp and Kc? -✓✓Kp = Kc
Under what circumstances are Kp and Kc equal for the reaction:
aA + bB -><- cC + dD (all gases) ?
A. When a + b = c + d
B. When the reaction is reversible
C. When the K is small -✓✓A
When writing a equilibrium constant, what phases are present and which do not
appear? -✓✓Gases and aqueous are present
Solids and liquids do not appear
What do you do if you do not know all the equilibrium concentrations? -✓✓ICE table
What is the reaction quotient (Q) ? -✓✓The reaction quotient is the ratio of the
concentrations of the products of a reaction to the concentrations of the reactants at a
particular time NOT at equilibrium.
Same as K but you may not be at equilibrium
What does the Q value tell you? -✓✓How the reaction will shift to get to equilibrium.
Can the Q value change over time? -✓✓Yes.
Verified Answers | 100% Correct |
Verified
Which statement does NOT generally apply to a chemical rxn in dynamic equilibrium?
A. The rates of the forward & reverse rxns are equal
B. The concentration of the reactants and the products are constant
C. The concentration of the reactants and the products are equal -✓✓C
The reactants and the products concentrations do not need to be the same.
What is the equilibrium constant? -✓✓The rate of equilibrium of concentration of
products raised to their stoichiometric coefficients divided by the concentrations of
reactants raised to their stoichiometric coefficients.
What can a high K value represent? [ K > 1 ] -✓✓Products dominant the reaction.
Reaction is favored to the right.
What can a low K value represent? [ K < 1 ] -✓✓Reactants dominant the reaction.
Reaction is favored to the left.
What can we tell about the chemical reaction just be looking at the K value? -✓✓The
magnitude of the equilibrium constant tells us whether a reaction favors products or
reactants at equilibrium.
What can you infer when the K constant is equal to 1? -✓✓Comparable amounts of
products and reactants are present at equilibrium.
The equilibrium constant for the reaction A (g) -> <- B (g) = 10. A reaction mixture
initially contains [A] = 1.1 M and [B] = 0.0 M. Which statement about this reaction is true
at equilibrium?
A. The equilibrium reaction mixture contains [A] = 1.0 M and [B] = 0.1 M
B. The equilibrium reaction mixture contains [A] = 0.1 M and [B] = 1.0 M
C. The equilibrium reaction mixture contains equal concentrations of A and B. -✓✓B
because K = 10
If you reverse an equilibrium reaction, what do you do to the initial K value? -✓✓Invert it.
If K = 10
K now becomes 1/10
, If you multiply the coefficients of an equilibrium reaction, what do you do to the initial K
value? -✓✓Raise the K to the same factor.
If you multiplied by 2
Raise K to the 2 (K^2)
If you add two or more reactions to obtain an overall one, what do you do to the initial
K? -✓✓Multiply the corresponding K constants by each other.
K1 x K2
In what two ways can you write equilibrium constants? -✓✓Kp and Kc
What is a Kc value? -✓✓Equilibrium constant using concentrations
What is a Kp value? -✓✓Equilibrium constant using partial pressures.
What must be true about the phases in the equilibrium reaction, to use a Kp? -✓✓All
must be in gaseous phases.
How do Kc and Kp relate? -✓✓Kp = Kc (RT) ^ Δn
If the total number of moles of gas is the same after the reaction as before than Δn,
what is true about Kp and Kc? -✓✓Kp = Kc
Under what circumstances are Kp and Kc equal for the reaction:
aA + bB -><- cC + dD (all gases) ?
A. When a + b = c + d
B. When the reaction is reversible
C. When the K is small -✓✓A
When writing a equilibrium constant, what phases are present and which do not
appear? -✓✓Gases and aqueous are present
Solids and liquids do not appear
What do you do if you do not know all the equilibrium concentrations? -✓✓ICE table
What is the reaction quotient (Q) ? -✓✓The reaction quotient is the ratio of the
concentrations of the products of a reaction to the concentrations of the reactants at a
particular time NOT at equilibrium.
Same as K but you may not be at equilibrium
What does the Q value tell you? -✓✓How the reaction will shift to get to equilibrium.
Can the Q value change over time? -✓✓Yes.
