Rate Constant and its Units NEET Questions

Physical Chemistry - Chemical Kinetics

Rate Constant and its Units MCQ Questions


1.
The rate constant (k) of a chemical reaction is defined as:
A.
The proportionality constant relating the rate of reaction to the concentrations of reactants raised to appropriate powers
B.
The total number of collisions between reactant molecules per second
C.
The rate of reaction at any concentration
D.
The maximum possible rate of a reaction
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ANSWER :
A. The proportionality constant relating the rate of reaction to the concentrations of reactants raised to appropriate powers
2.
In the rate law Rate = k[A]^m [B]^n, the rate constant k:
A.
Increases as [A] increases
B.
Decreases as [B] increases
C.
Is equal to the rate when [A] = [B]
D.
Is independent of the concentrations of A and B
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ANSWER :
D. Is independent of the concentrations of A and B
3.
The rate constant of a reaction depends on:
A.
Volume of the reaction vessel
B.
Temperature and the presence of a catalyst
C.
Concentrations of reactants only
D.
Concentrations of products only
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ANSWER :
B. Temperature and the presence of a catalyst
4.
When [A] = [B] = 1 mol L⁻¹ in the rate law Rate = k[A]^m [B]^n, the rate equals:
A.
Zero
B.
k × (m + n)
C.
k/(m + n)
D.
k (numerically equal to the rate constant)
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ANSWER :
D. k (numerically equal to the rate constant)
5.
The numerical value of the rate constant for a reaction depends on:
A.
Units of concentration and time chosen, as well as temperature
B.
Initial concentration only
C.
Stoichiometric coefficients only
D.
Volume of the container only
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ANSWER :
A. Units of concentration and time chosen, as well as temperature
6.
The general formula for the units of the rate constant for an n-th order reaction (with concentration in mol L⁻¹ and time in s) is:
A.
(mol L⁻¹)^n s⁻¹
B.
(mol L⁻¹)^(1−n) s⁻¹
C.
(mol L⁻¹)^(n−1) s⁻¹
D.
mol L⁻¹ s⁻ⁿ
😑 View Answer Rough Work Error
ANSWER :
B. (mol L⁻¹)^(1−n) s⁻¹