A gas absorbs $$200 \mathrm{~J}$$ heat and expands by $$500 \mathrm{~cm}^3$$ against a constant external pressure $$2 \times 10^5 \mathrm{~N} \mathrm{~m}^{-2}$$. What is the change in internal energy?
Identify a copolymer from following.
Find the average rate of formation of $$\mathrm{NO}_{2(\mathrm{~g})}$$, in following reaction.
$$\begin{aligned} & 2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} \\ & {\left[-\frac{\Delta\left[\mathrm{N}_2 \mathrm{O}_5\right]}{\Delta \mathrm{t}}\right]=x \mathrm{~mol} \mathrm{~dm}^{-3} \mathrm{~s}^{-1}} \end{aligned}$$
Calculate the rate constant for the first order reaction, $$\mathrm{A} \rightarrow \mathrm{B}$$ if the rate of reaction is $$5.4 \times 10^{-6} \mathrm{~mol} \mathrm{~dm}^{-3} \mathrm{~s}^{-1}$$ and $$[\mathrm{A}]=0.3 \mathrm{M}$$.