$$\mathrm{r}=\mathrm{k}[\mathrm{A}]$$ for a reaction, $$50 \%$$ of $$\mathrm{A}$$ is decomposed in 120 minutes. The time taken for $$90 \%$$ decomposition of $$\mathrm{A}$$ is _________ minutes.

$$\mathrm{NO}_2$$ required for a reaction is produced by decomposition of $$\mathrm{N}_2 \mathrm{O}_5$$ in $$\mathrm{CCl}_4$$ as by equation

$$2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$$

The initial concentration of $$\mathrm{N}_2 \mathrm{O}_5$$ is $$3 \mathrm{~mol} \mathrm{~L}^{-1}$$ and it is $$2.75 \mathrm{~mol} \mathrm{~L}^{-1}$$ after 30 minutes.

The rate of formation of $$\mathrm{NO}_2$$ is $$\mathrm{x} \times 10^{-3} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~min}^{-1}$$, value of $$\mathrm{x}$$ is _________. (nearest integer)

The rate of First order reaction is $$0.04 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ at 10 minutes and $$0.03 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ at 20 minutes after initiation. Half life of the reaction is _______ minutes.

(Given $$\log 2=0.3010, \log 3=0.4771$$)

The half-life of radioisotope bromine - 82 is 36 hours. The fraction which remains after one day is ________ $$\times 10^{-2}$$.

(Given antilog $$0.2006=1.587$$)