Question

The rate of the reaction does not depend upon:
(A) Temperature
(B) Concentration
(C) Catalyst
(D) None of these

Answer 1

Hint: The rate of the reaction is the ratio of the change in the reactant concentration to the time needed for that change. The rate of the reaction is also expressed as the ratio of the change in the reactant partial pressure to the time needed for that change.The factors that increase the number of effective collisions per unit time, also increases the rate of the reaction.

Complete answer:
Consider a general reaction \[{\text{A }} \to {\text{ products}}\] .
All the three factors, temperature, concentration and catalyst affect the rate of the reaction.
The rate of the reaction increases when the reactant concentration is increased. For nth order reaction, the rate of the reaction is directly proportional to the nth power of reactant concentration.
\[{\text{rate }} = {\text{ k}}{\left[ {\text{A}} \right]^n}\]
Similarly, the rate of the reaction increases when the reactant partial pressure is increased.
For nth order reaction, the rate of the reaction is directly proportional to the nth power of reactant partial pressure.
\[{\text{rate }} = {\text{ k}} \times {P_{\text{A}}}^n\]
The rate of the reaction is also increased by the presence of a catalyst. A catalyst increases the rates of forward and reverse reactions. So the equilibrium is quickly attained. A catalyst provides an alternate pathway of lower activation energy.
Temperature change also affects the rates of chemical reaction when the temperature is increased by about \[{\text{10 K}}\] the rate of the reaction is doubled. The effect of temperature on the rate of the chemical reaction has industrial importance, as the batch in a plant can be completed in less time by increasing the temperature so that the rate of the reaction increases.

So the correct answer is D).

Note: There are two types of catalysis, positive catalysis and negative catalysis. A positive catalyst increases the rate of the reaction whereas the negative catalyst decreases the rate of the reaction. A negative catalyst acts as a poison.