Equilibrium NDA Questions

NDA Chemistry

Equilibrium MCQ Questions


7.
A chemical equilibrium is said to be attained in a reversible reaction when:
A.
The rates of the forward and backward reactions become equal and the concentrations of reactants and products become constant
B.
Only reactants remain in the system
C.
The reaction has stopped completely
D.
The reaction goes to 100% completion
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ANSWER :
A. The rates of the forward and backward reactions become equal and the concentrations of reactants and products become constant
8.
Chemical equilibrium in a closed vessel is best described as:
A.
Achieved only when reactants are completely consumed
B.
Dynamic in nature, since both forward and reverse reactions continue to occur at equal rates
C.
Static in nature, with no molecular motion
D.
Independent of temperature and pressure
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ANSWER :
B. Dynamic in nature, since both forward and reverse reactions continue to occur at equal rates
9.
The Law of Mass Action, proposed by Guldberg and Waage, states that the rate of a chemical reaction is directly proportional to:
A.
The product of the molar concentrations of the reactants, each raised to a power equal to its stoichiometric coefficient
B.
The volume of the container
C.
The number of moles of products formed
D.
The temperature of the reaction only
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ANSWER :
A. The product of the molar concentrations of the reactants, each raised to a power equal to its stoichiometric coefficient
10.
For a general reversible reaction aA + bB ⇌ cC + dD at equilibrium, the equilibrium constant Kc is given by:
A.
Kc = [A][B] / [C][D]
B.
Kc = [A]^a[B]^b / [C]^c[D]^d
C.
Kc = [C][D] - [A][B]
D.
Kc = [C]^c[D]^d / [A]^a[B]^b
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ANSWER :
D. Kc = [C]^c[D]^d / [A]^a[B]^b
11.
The equilibrium constant (Kc) of a reaction at a given temperature is related to the equilibrium constant of the reverse reaction (Kc') by:
A.
Kc = 1/Kc'
B.
Kc = -Kc'
C.
Kc = (Kc')^2
D.
Kc = Kc'
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ANSWER :
A. Kc = 1/Kc'
12.
If the equation for a reaction is doubled (multiplied by 2), the new equilibrium constant K' is related to the original Kc as:
A.
K' = 2Kc
B.
K' = (Kc)^2
C.
K' = square root of Kc
D.
K' = Kc/2
😑 View Answer Rough Work Error
ANSWER :
B. K' = (Kc)^2