Half-life period of a first order reaction is $1386$ seconds. The specific rate constant of the reaction is

$Zn + 2H^+ \to  Zn^{2+} + H_2$

The half-life period is independent of the concentration of zinc at constant $pH$. For the constant concentration of $Zn$, the rate becomes $100$ times when $pH$ is decreased from $3\, to\, 2$. Identify the correct statements $(pH = -\log [H^{+}])$

$(A)$  $\frac{{dx}}{{dt}}\, = k{[Zn]^0}{[{H^ + }]^2}$

$(B)$  $\frac{{dx}}{{dt}}\, = k{[Zn]}{[{H^ + }]^2}$

$(C)$ Rate is not affected if the concentraton of zinc is made four times and that of $H^+$ ion is halved.

$(D)$ Rate becomes four times if the concentration of $H^+$ ion is doubled at constant $Zn$ concentration

The specific rate constant of a first order reaction depends on the

The following results were obtained during kinetic studies of the reaction $2A+B$ $\to$ products

The time(in minutes) required to consume half of $A$ is

The rate constant for the reaction, $2N_2O_5 \to 4NO_2 + O_2$ is $3.0\times 10^{- 4}\,s^{-1}$ . If start made with $1.0\,mol\,L^{-1}$ of $N_2O_5$, calculate the rate of formation of $NO_2$ at the moment of the reaction when concentration of $O_2$ is $0.1\, mol\, L^{-1}$.

Mechanism of a hypothetical reaction

$X_2 + Y_2 \rightarrow 2XY,$ is given below :

$(i)\,\, X_2 \rightarrow X + X\, (fast)$

$(ii)\,\,X + Y_2 \rightleftharpoons XY + Y\, (slow)$

$(iii)\,\,X + Y \rightarrow XY\, (fast)$

The overall order of the reaction will be