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

The above reaction is of zero order. Half life of this reaction is $$50 \mathrm{~min}$$. The time taken for the concentration of $$\mathrm{A}$$ to reduce to one-fourth of its initial value is ____________ min. (Nearest integer)

A and B are two substances undergoing radioactive decay in a container. The half life of A is 15 min and that of B is 5 min. If the initial concentration of B is 4 times that of A and they both start decaying at the same time, how much time will it take for the concentration of both of them to be same? _____________ min.

(Given : $\ln 10=2.303$ and $$ \log 2=0.3010 \text { )}$$

A $$\to$$ B

The rate constants of the above reaction at 200 K and 300 K are 0.03 min$$^{-1}$$ and 0.05 min$$^{-1}$$ respectively. The activation energy for the reaction is ___________ J (Nearest integer)

(Given : $$\mathrm{ln10=2.3}$$

$$\mathrm{R=8.3~J~K^{-1}~mol^{-1}}$$

$$\mathrm{\log5=0.70}$$

$$\mathrm{\log3=0.48}$$

$$\mathrm{\log2=0.30}$$)