(C) For a first order reaction,the rate constant $K$ is given by the formula: $K = \frac{2.303}{t} \log \frac{[A]_0}{[A]_t}$ Given: $[A]_0 = 0.4 \, M$

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(C) For a first order reaction,the rate constant $K$ is given by the formula: $K = \frac{2.303}{t} \log \frac{[A]_0}{[A]_t}$ Given: $[A]_0 = 0.4 \, M$,$[A]_t = 0.1 \, M$,and $t = 20 \, \min$. Substituting the values: $K = \frac{2.303}{20} \log \frac{0.4}{0.1} = \frac{2.303}{20} \log 4$ Since $\log 4 = 2 \log 2 \approx 2 \times 0.3010 = 0.6020$: $K = \frac{2.303 \times 0.6020}{20} \approx \frac{1.386}{20} = 0.0693 \, \min^{-1}$.

Class 12 Chemistry Chemical Kinetics First Order reaction

Medium

In a first order reaction,the concentration of the reactant decreased from $0.4 \, M$ to $0.1 \, M$ in $20 \, \min$. The rate constant of the reaction will be:

A
$0.693 \, \min^{-1}$
B
$6.93 \, \min^{-1}$
C
$0.0693 \, \min^{-1}$
D
$69.3 \, \min^{-1}$

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First Order reaction

The rate of a first order reaction is $1.5 \times 10^{-2} \ mol \ L^{-1} \ \min^{-1}$ at $0.5 \ M$ concentration of the reactant. The half life of the reaction is ....... $\min$

MediumAIPMT 2004

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If the rate constant is $1.155 \times 10^{-3} \ s^{-1}$,after how many seconds will the concentration of the reactant be reduced to half in a first-order reaction?

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When the value of rate constant $(k)$ is $2.0 \text{ min}^{-1}$, then what will be the half-life of the reaction $(t_{1/2})$ in seconds?

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Which of the following graphs represents a first-order reaction?

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For a first-order reaction,the concentration of the reactant decreases from $0.8 \, M$ to $0.4 \, M$ in $15 \, \text{minutes}$. The time required for the concentration to change from $0.1 \, M$ to $0.025 \, M$ is ....... $\text{min}$.

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In a first order reaction,the concentration of the reactant decreased from $0.4 \, M$ to $0.1 \, M$ in $20 \, \min$. The rate constant of the reaction will be:

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The rate of a first order reaction is $1.5 \times 10^{-2} \ mol \ L^{-1} \ \min^{-1}$ at $0.5 \ M$ concentration of the reactant. The half life of the reaction is ....... $\min$

If the rate constant is $1.155 \times 10^{-3} \ s^{-1}$,after how many seconds will the concentration of the reactant be reduced to half in a first-order reaction?

When the value of rate constant $(k)$ is $2.0 \text{ min}^{-1}$, then what will be the half-life of the reaction $(t_{1/2})$ in seconds?

Which of the following graphs represents a first-order reaction?

For a first-order reaction,the concentration of the reactant decreases from $0.8 \, M$ to $0.4 \, M$ in $15 \, \text{minutes}$. The time required for the concentration to change from $0.1 \, M$ to $0.025 \, M$ is ....... $\text{min}$.

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