Which of the following electromagnetic radiations possesses lowest energy?

Which among the following is an example of branched chain polymer?

For the reaction,

$$\mathrm{CH}_3 \mathrm{Br}(a q)+\mathrm{OH}^{-}(a q) \longrightarrow \mathrm{CH}_3 \mathrm{OH}(a q)+\mathrm{Br}^{-}(a q),$$

The rate law is rate $$=k\left[\mathrm{CH}_3 \mathrm{Br}\right]\left[\mathrm{OH}^{-}\right]$$. What is change in rate of reaction if concentration of both reactants is doubled?

For the reaction, $$2 A+2 B \longrightarrow 2 C+D$$, the rate law is expressed as rate $$=k[A]^2[B]$$. Calculate the rate constant if rate of reaction is $$0.24 \mathrm{~mol} \mathrm{~dm}^{-3} \mathrm{~s}^{-1}$$.

[[$$A$$]$$=0.5 \mathrm{M}$$ and $$[B]=0.2 \mathrm{M}$$]