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WorksheetsChemical Equilibrium Quiz
Total questions: 24
Worksheet time: 43mins
What is the equilibrium constant?
The equilibrium constant is the temperature at which a reaction reaches equilibrium.
The equilibrium constant is the total amount of reactants in a system.
The equilibrium constant is the ratio of the concentrations of the products to the concentrations of the reactants.
The equilibrium constant is the rate at which a reaction occurs.
How is the reaction quotient calculated?
By subtracting the concentrations of the products from the concentrations of the reactants.
By multiplying the concentrations of the products by the concentrations of the reactants.
By dividing the concentrations of the products by the concentrations of the reactants, each raised to the power of their respective stoichiometric coefficients.
By adding the concentrations of the products to the concentrations of the reactants.
Provide an example of Le Chatelier's principle in action.
An example of Le Chatelier's principle in action is when a reaction is endothermic (absorbs heat) and the temperature is increased. According to Le Chatelier's principle, the system will shift to release more heat, thus reducing the temperature.
An example of Le Chatelier's principle in action is when a reaction is exothermic (releases heat) and the temperature is increased. According to Le Chatelier's principle, the system will shift to absorb the excess heat by favoring the endothermic reaction, thus reducing the temperature.
An example of Le Chatelier's principle in action is when a reaction is exothermic and the pressure is increased. According to Le Chatelier's principle, the system will shift to decrease the pressure by favoring the reaction that produces fewer moles of gas.
An example of Le Chatelier's principle in action is when a reaction is exothermic and the temperature is decreased. According to Le Chatelier's principle, the system will shift to release more heat, thus increasing the temperature.
What are the factors that can affect equilibrium?
Volume, time, and pH.
Density, color, and viscosity.
Temperature, pressure, concentration.
Mass, speed, and pH.
Write the equilibrium expression for the given chemical reaction: A + B ⇌ C + D
K = [A][C]/[B][D]
K = [C][D]/[B][A]
K = [C][D]/[A][B]
K = [A][B]/[C][D]
What does a high equilibrium constant indicate?
The reaction strongly favors the formation of products over reactants.
The reaction does not favor the formation of either reactants or products.
The reaction is at equilibrium with equal amounts of reactants and products.
The reaction strongly favors the formation of reactants over products.
How does temperature affect equilibrium?
Temperature increases the rate of reaction at equilibrium.
Temperature has no effect on equilibrium.
Temperature decreases the concentration of reactants at equilibrium.
Temperature affects equilibrium by shifting the position of the equilibrium.
Explain the concept of dynamic equilibrium.
A state in a system where the reverse reaction occurs faster than the forward reaction, resulting in a decrease in the concentration of reactants over time.
A state in a system where the forward reaction occurs faster than the reverse reaction, resulting in an increase in the concentration of products over time.
A state in a system where the forward and reverse reactions occur at different rates, resulting in a gradual change in the concentrations of reactants and products over time.
A state in a system where the forward and reverse reactions occur at the same rate, resulting in no net change in the concentrations of reactants and products over time.
What happens to the equilibrium position when pressure is increased?
The equilibrium position shifts towards the side with more moles of gas.
The equilibrium position remains unchanged.
The equilibrium position disappears.
The equilibrium position shifts towards the side with fewer moles of gas.
What is the role of a catalyst in a chemical reaction at equilibrium?
A catalyst does not affect the equilibrium position or concentrations at equilibrium.
A catalyst increases the equilibrium position of the reaction.
A catalyst decreases the concentrations at equilibrium.
A catalyst changes the equilibrium constant of the reaction.
2A + 3B <----> 2AB
The reverse reaction forms the substance __________.
A
B
AB
A + B
Which of the following is NOT true at equilibrium?
The forward and reverse reactions proceed at the same rate.
The concentrations of reactants and products do not change.
The concentration of the reactants is equal to the concentration of the products.
The forward and reverse reactions continue to occur.
For the reaction...
heat + N2 + O2 ↔ 2NO
If the heat is added to the chemical system, the equilibrium will shift _______.
left
right
left and right
neither left nor right
For the reaction...
H2 (g) + Cl2 (g) <−> 2HCl (g) + heat
If the temperature is cooled, the _________ reaction will be favored.
forward
reverse
forward and reverse
For the reaction...
heat + N2 + O2 <−> 2NO
If NO is removed from the system, the concentration of N2 will _______.
increase
decrease
remain the same
double
The following factors affect the position of equilibrium EXCEPT
Concentration
State of Matter
Temperature
Pressure
What is the effect of increasing the pressure on the following equilibrium: 2NO(g) + O2 (g) ⇌2NO2(g)?
The yield of NO2 increases
The yield of NO2 decreases
The reaction is slower
The concentration of O2 increases.
Consider this system:
2CCl4(g) + O2(g)<->2COCl2(g) + 2Cl2(g) ΔH = -35 kJ/molrxn
Predict the effect of increasing temperature.
Speed up forward reaction.
Speed up reverse reaction.
No change.
For the reaction...
N2 (g) + 3 H2(g) ⇌ 2 NH3 (g)
If the pressure in the system is decreased, which substance(s) will increase in concentration?
N2
H2
N2 and H2
NH3
What is the equilibrium expression for:
Fe3O4(s) + 4H2(g) <=> 3Fe(s) + 4H2O(g)
Kc =
[Fe]3 [H2O]4 / [Fe3O4] [H2]4
[Fe3O4] [H2]4 / [Fe]3 [H2O]4
[H2O]4 / [H2]4
[Fe] [H2O] / [Fe3O4] [H2]
If Q = [A]m[B]n[C]x[D]y and the equation is 4NH3(g) + 7O2(g) ⇌ 4NO2(g) + 6H2O(g). What is the value of n?
7
2
3
6
CHECK YOUR LEARNING.
For the reaction
4NH3(g) + 7O2(g) ⇌ 4NO2(g) + 6H2O(g)
the concentrations at equilibrium are [NH3] = 0.17 M, [O2] = 2.8 M, and [NO2] = 7.7 M, [H2O] = 0.3 M
What is the value of the equilibrium constant, Kc?
(a)
CHECK YOUR LEARNING.
For the reaction
N2(g) + 3H2(g) ⇌ 2NH3(g)
The equilibrium mixture of gases was analyzed and found to contain 1.45 atm for N2, 0.47 atm for H2, and 0.77 atm NH3.
From these data, calculate the equilibrium constant Kp for the reaction:
(a)
What is the value of K when equilibrium favors the products and equilibrium lies to the right?
>1
<1
1
0
