A molecule undergoes two independent first order reactions whose respective half lives are 12 min and 3 min. If both the reactions are occurring then the time taken for the 50% consumption of the reactant is ___________ min. (Nearest integer)

Time required for completion of $99.9 \%$ of a First order reaction is ________ times of half life $\left(t_{1 / 2}\right)$ of the reaction.

The number of incorrect statement/s from the following is ___________

A. The successive half lives of zero order reactions decreases with time.

B. A substance appearing as reactant in the chemical equation may not affect the rate of reaction

C. Order and molecularity of a chemical reaction can be a fractional number

D. The rate constant units of zero and second order reaction are $\mathrm{mol} ~\mathrm{L}^{-1} \mathrm{~s}^{-1}$ and respectively

$\mathrm{t}_{87.5}$ is the time required for the reaction to undergo $87.5 \%$ completion and is the time required for the reaction to undergo completion. The relation between and for a first order reaction is The value of is ___________. (Nearest integer)

A(g) $\to$ 2B(g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be _________ mm Hg. (Nearest integer)

For the first order reaction A $\to$ B, the half life is 30 min. The time taken for 75% completion of the reaction is _________ min. (Nearest integer)

Given : log 2 = 0.3010

log 3 = 0.4771

log 5 = 0.6989

Assuming $1 \,\mu \mathrm{g}$ of trace radioactive element X with a half life of 30 years is absorbed by a growing tree. The amount of X remaining in the tree after 100 years is ______ $\times\, 10^{-1} \mu \mathrm{g}$.

For the given first order reaction

$\mathrm{A} \rightarrow \mathrm{B}$

the half life of the reaction is $0.3010 \mathrm{~min}$. The ratio of the initial concentration of reactant to the concentration of reactant at time will be equal to ___________. (Nearest integer)

For a first order reaction A $\to$ B, the rate constant, k = 5.5 $\times$ 10^$-$14 s^$-$1 times the half life of reaction. The value of x is _____________ (Nearest integer)

A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ___________. (Nearest integer)

(Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)

For conversion of compound A $\to$ B, the rate constant of the reaction was found to be $\mathrm{4.6\times10^{-5}~L~mol^{-1}~s^{-1}}$. The order of the reaction is ____________.

Consider the following reaction

$\mathrm{A}+\mathrm{B} \rightarrow \mathrm{C}$

The time taken for A to become $1 / 4^{\text {th }}$ of its initial concentration is twice the time taken to become of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight line with a negative slope and a positive intercept on the concentration axis.

Consider the following first order gas phase reaction at constant temperature $\mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{B}(\mathrm{~g})+\mathrm{C}(\mathrm{g})$

$2 \mathrm{NO}+2 \mathrm{H}_{2} \rightarrow \mathrm{N}_{2}+2 \mathrm{H}_{2} \mathrm{O}$

The half life for the decomposition of gaseous compound $\mathrm{A}$ is $240 \mathrm{~s}$ when the gaseous pressure was 500 Torr initially. When the pressure was 250 Torr, the half life was found to be $4.0$ min. The order of the reaction is ______________. (Nearest integer)