For reaction $\mathrm{A}+\mathrm{B} \rightarrow$ product, rate of reaction is $3.6 \times 10^{-2} \mathrm{sec}^{-1}$. When $[\mathrm{A}]=0.2 \mathrm{moldm}^{-3}$ and $[B]=0.1 \mathrm{moldm}^{-3}$, calculate rate constant of reaction if reaction is first order in A and second order is B ?

Which of following polymer does not contain

Unit cell of an element has edge length of 5$$\mathop A\limits^o $$ with density $4 \mathrm{~g} \mathrm{~cm}^{-3}$, if its atomic mass is 149, identify the crystal structure.

Which among the following gases is difficult to liquify?