What is the effect of temperature on the rate constant of a reaction? How can this temperature effect on rate constant be represented quantitatively?
What is the effect of temperature on the rate constant of a reaction? How can this temperature effect on rate constant be represented quantitatively?
Solution and Explanation
The rate constant is nearly doubled with a rise in temperature by 10°C for a chemical reaction.
The temperature effect on the rate constant can be represented quantitatively by Arrhenius equation,
\(k = Ae^{-\frac {E_a}{RT}}\)
where,
k is the rate constant,
A is the Arrhenius factor or the frequency factor,
R is the gas constant,
T is the temperature, and
Ea is the energy of activation for the reaction
Top Questions on Chemical Kinetics
Rate law for a reaction between $A$ and $B$ is given by $\mathrm{R}=\mathrm{k}[\mathrm{A}]^{\mathrm{n}}[\mathrm{B}]^{\mathrm{m}}$. If concentration of A is doubled and concentration of B is halved from their initial value, the ratio of new rate of reaction to the initial rate of reaction $\left(\frac{\mathrm{r}_{2}}{\mathrm{r}_{1}}\right)$ is
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- Consider the following statements related to temperature dependence of rate constants. Identify the correct statements,
A. The Arrhenius equation holds true only for an elementary homogeneous reaction.
B. The unit of A is same as that of k in Arrhenius equation.
C. At a given temperature, a low activation energy means a fast reaction.
D. A and Ea as used in Arrhenius equation depend on temperature.
E. When Ea >> RT. A and Ea become interdependent.
Choose the correct answer from the options given below :- JEE Main - 2025
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Concepts Used:
Rate of a Chemical Reaction
The rate of a chemical reaction is defined as the change in concentration of any one of the reactants or products per unit time.
Consider the reaction A → B,
Rate of the reaction is given by,
Rate = −d[A]/ dt=+d[B]/ dt
Where, [A] → concentration of reactant A
[B] → concentration of product B
(-) A negative sign indicates a decrease in the concentration of A with time.
(+) A positive sign indicates an increase in the concentration of B with time.
Factors Determining the Rate of a Reaction:
There are certain factors that determine the rate of a reaction:
- Temperature
- Catalyst
- Reactant Concentration
- Chemical nature of Reactant
- Reactant Subdivision rate