Question:medium

The rate constants $k_1$ and $k_2$ for two different reactions are $10^{16} .e^{-2000/T}$ and $10^{15} .e^{-1000/T}$,respectively. The temperature at which $k_1= k_2$ is

Updated On: Jun 10, 2026
  • 1000 K
  • $\frac{2000}{2.303} K$
  • 2000 K
  • $\frac{1000}{2.303} K$
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The Correct Option is D

Solution and Explanation

To determine the temperature at which the rate constants \(k_1\) and \(k_2\) are equal, we need to equate the two expressions for \(k_1\) and \(k_2\):

The given expressions for the rate constants are:

\(k_1 = 10^{16} \cdot e^{-2000/T}\) and \(k_2 = 10^{15} \cdot e^{-1000/T}\)

At the temperature where \(k_1 = k_2\), we have:

\(10^{16} \cdot e^{-2000/T} = 10^{15} \cdot e^{-1000/T}\)

Dividing both sides by \(10^{15}\), we get:

\(10 \cdot e^{-2000/T} = e^{-1000/T}\)

Taking the natural logarithm on both sides, we have:

\(\ln(10) + \ln(e^{-2000/T}) = \ln(e^{-1000/T})\)

This simplifies to:

\(\ln(10) - \frac{2000}{T} = -\frac{1000}{T}\)

Rearranging the terms, we can solve for \(T\):

\(\ln(10) = \frac{2000}{T} - \frac{1000}{T}\)

\(\ln(10) = \frac{1000}{T}\)

Thus, \(T = \frac{1000}{\ln(10)}\)

Using the approximation \(\ln(10) = 2.303\), we substitute to find \(T\):

\(T = \frac{1000}{2.303}\) K

Therefore, the correct answer is $\frac{1000}{2.303} K$.

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