For a first-order reaction,which of the follo | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) For a first-order reaction,the integrated rate law is given by $[A]_t = [A]_0 e^{-kt}$.The degree of dissociation (or fraction reacted) $\alpha$ i

Vedclass · Accepted Answer

The degree of dissociation is equal to $(1 - e^{-kt})$.

Vedclass · Answer

(A) For a first-order reaction,the integrated rate law is given by $[A]_t = [A]_0 e^{-kt}$.The degree of dissociation (or fraction reacted) $\alpha$ is given by $\alpha = \frac{[A]_0 - [A]_t}{[A]_0} = 1 - \frac{[A]_t}{[A]_0} = 1 - e^{-kt}$.Thus,option $A$ is correct.In the Arrhenius equation $k = A e^{-E_a/RT}$,the pre-exponential factor $A$ has the same units as the rate constant $k$. For a first-order reaction,the unit of $k$ is $s^{-1}$,which is the reciprocal of time,not time itself. Therefore,option $B$ is incorrect.For a first-order reaction,the plot of $\ln[A]$ versus time is a straight line,not the reciprocal of concentration. Therefore,option $C$ is incorrect.

Experiment	$[A]$ $(mol \ L^{-1})$	$[B]$ $(mol \ L^{-1})$	Initial rate $(mol \ L^{-1} \ min^{-1})$
$I$	$0.10$	$0.20$	$6.93 \times 10^{-3}$
$II$	$0.10$	$0.25$	$6.93 \times 10^{-3}$
$III$	$0.20$	$0.30$	$1.386 \times 10^{-2}$

For a first-order reaction,which of the following statements is correct?

Similar Questions

If the concentration unit decreases by a factor of $n$,what will be the value of the rate constant for a first-order reaction?

The half-life of a first-order reaction is $900 \text{ s}$. If the initial concentration of the reactant is $0.08 \text{ mol dm}^{-3}$, find the concentration that remains after $35 \text{ minutes}$?

The reaction $A + B \xrightarrow{k}$ product is first order with respect to $A$ and zero order with respect to $B$. If $a_0$ and $a_t$ are the concentrations of $A$ at $t = 0$ and after time $t \, sec$ respectively,then select the correct relationship -

For a first-order gas-phase reaction $A(g) \to B(g) + C(g)$, let $p_i$ be the initial pressure of gas $A$ and $p_t$ be the total pressure of the reaction mixture at time $t$. The expression for the rate constant $(k)$ is:

Vedclass Test Series

Exam Paper Generator

Online Exam Module