The rate of a gaseous reaction is given by the expression $$k[A][B]^2$$. If the volume of vessel is reduced to one half of the initial volume, the reaction rate as compared to original rate is

Higher order $$(>3)$$ reactions are rare due to

The time required for $$60 \%$$ completion of a first order reaction is $$50 \mathrm{~min}$$. The time required for $$93.6 \%$$ completion of the same reaction will be

For an elementary reaction $$2 A+3 B \rightarrow 4 C+D$$ the rate of appearance of $C$ at time '$$T$$' is $$2.8 \times 10^{-3} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~S}^{-1}$$. Rate of disappearance of $$B$$ at '$$t$$' $t$ will be