$Zn + 2H^+ \to  Zn^{2+} + H_2$

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

• A

  $A,C$

• B

  $A,C$ and $D$

• C

  $B,C$ and $D$

• D

  None