Worksheetschemeq1
Total questions: 16
Worksheet time: 9mins
Which of the following is an example of homogeneous equilibrium?
2H2O (l) ⇋ 2 H2 (g) + O2 (g)
3 Fe (s) + 4 H2O (g) ⇋ Fe3O4 (s) + 4 H2 (g)
PCl5 (g) ⇋ Cl2 (g) + PCl3 (g)
2 C (s) + O2 (g) ⇋ 2 CO (g)
Which of the following statements is true when an equilibrium mixture achieves dynamic equilibrium?
The chemical decomposition of the system changes with time.
There are no more products formed or reactants being used up.
The concentrations of all the reactants and products remain constant.
The equilibrium position is halfway between the products and reactants.
Which of the following is correct when the system; P + Q ⇋ R + S; achieves equilibrium?
[P] [Q] = [R] [S]
[P] [Q] > [R] [S]
K1 = K-1
([P] [Q]/[R] [S]) = constant
Carbon monoxide will react with steam under appropriate conditions as represented by the equation;
CO (g) + H2O (g) ⇋ CO2 (g) + H2 (g)
∆H = -40 kJmol-1
When the system is at equilibrium;
The forward and backward reactions come to a stop.
The forward and backward reactions are proceeding at different rates.
The concentration of CO (g), H2O (g), CO2 (g) and H2 (g) remain constant.
The concentration of CO (g), H2O (g), CO2 (g) and H2 (g) remain the same.
Which of the following statements is true when a system is in a state of equilibrium?
A + B ⇋ C + D
Concentration of A, B, C and D become constant.
Forward reaction will stop.
[A] = [B] = [C] = [D]
The mass of A + B = the mass of C + D
Which equilibrium has the value of Kc = Kp?
Br2 (g) ⇋ 2 Br (g)
3 Fe (s) + 4 H2O (g) ⇋ Fe3O4 (s) + 4 H2 (g)
N2 (g) + 3 H2 (g) ⇋ 2NH3 (g)
C2H5OH (l) + CH3COOH (l) ⇋ CH3COOC2H5 (l) + H2O (l)
What is the relationship between equilibrium constant, Kc, and the rate constant of a reversible reaction.
(K1 = rate constant of forward reaction)
(K2 = rate constant of backward reaction)
Kc = K1 x K2
Kc = K1 + K2
Kc = K1/K2
Kc = 1/(K1 x K2)
Which of the following statement is correct regarding a system in dynamic equilibrium?
All reactions have stopped.
The rate constant of the forward reaction equals that of the reverse reaction.
The rate of the forward reaction equals that of the reverse reaction.
The rate of the forward reaction equals the rate of reverse reaction and the rate constant of the forward reaction equals that of the reverse reaction.
The equilibrium constant for reaction I below is K. What is the equilibrium constant for reaction II?
SO2 (g) + ½ O2 (g) ⇋ SO3 (g) I
2 SO3 (g) ⇋ 2 SO2 (g) + O2 (g) II
K-2
K2
2K
2K-1
The Kc for the reaction below is 2.3 at 298 K:
X (l) + Y (l) ⇋ Z (l)
Which of the following graph of concentration against time is correct for the reaction, if equimolar of X, Y and Z were mixed at 298 K?
Consider the reaction : P ⇋ Q
rate of reaction for P → Q = K1
rate of reaction for Q → P = K2
The rate equation for the forward reaction is
K1 [P] [Q]
K1 [P]
K2 [P]
K1 K2 [P] [Q]
Consider the reversible reaction : P + Q ⇋ R + S
Which of the following statement is correct when the above system is in dynamic equilibrium?
The reaction in both directions stop.
The rate of reaction in both direction is different.
The concentration of P, Q, R and S remain constant.
The concentration of P, Q, R and S are the same.
Which of the following statement is correct regarding the following equilibrium?
H2 (g) + Cl2 (g) ⇋ 2 HCl (g)
I Kc = Kp
II Kc has the unit of mol2 dm-6
III Kp has the unit of Pa2
I only is correct
I and II are correct
II and III are correct
I, II and III are correct
In reversible reaction, dynamic equilibrium is reached when
I the activation energy of the forward reaction is equal to the activation energy of the reverse reaction.
II Rate of forward reaction is equal to the rate of reverse reaction.
III The concentration of the reactants and products does not change with time.
I only is correct
I and II are correct
II and III are correct
I, II and III are correct
When calcium carbonate is heated in a closed container, it dissociates into calcium oxide and carbon dioxide.
CaCO3 (s) ⇋ CaO (s) + CO2 (g)
The equilibrium constant for this reaction is
K = PCO2
K = [CaCO3]/[CaO] [CO2]
K = [CaO] [CO2]/[CaCO3]
K = PCaO x PCO2 / PCaCO3
Two equilibria are shown below:
Reaction I : 2 AB (g) + 2 C2 (g) ⇋ 2 AC2 (g) + B2 (g)
Reaction II : AC2 (g) + ½ B2 (g) ⇋ AB (g) + C2 (g)
The numerical value of Kc for reaction I is 28.2. Under the same conditions, what is the numerical value of Kc for reaction II?
0.19
2.82
5.31
14.10
