The half life for second order reaction is $30\, minutes$. If the initial concentration is $0.1\, M$ then the value of rate constant will be ............ $M^{-1}\, min^{-1}$

For a certain reaction, the rate $=k[A]^2[B]$, when the initial concentration of $A$ is tripled keeping concentration of $B$ constant, the initial rate would

$Zn + 2H^+ \to  Zn^{2+} + H_2$

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

Molecularity of reaction of inversion of sugar is

The concentration of $R$ in the reaction $R \rightarrow P$ was measured as a function of time and the following data is obtained:

The order of the reaction is

Consider the following single step reaction in gas phase at constant temperature.

$2 \mathrm{~A}_{(\mathrm{g})}+\mathrm{B}_{(\mathrm{g})} \rightarrow \mathrm{C}_{(\mathrm{g})}$

The initial rate of the reaction is recorded as $r_1$ when the reaction starts with $1.5 \mathrm{~atm}$ pressure of $\mathrm{A}$ and $0.7 \mathrm{~atm}$ pressure of B. After some time, the rate $r_2$ is recorded when the pressure of $C$ becomes $0.5 \mathrm{~atm}$. The ratio $r_1: r_2$ is $\qquad$ $\times 10^{-1}$.

(Nearest integer)