The products $$\mathrm{A}$$ and $$\mathrm{B}$$ obtained in the following reactions, respectively, are
$$\begin{aligned} & 3 \mathrm{ROH}+\mathrm{PCl}_3 \rightarrow 3 \mathrm{RCl}+\mathrm{A} \\ & \mathrm{ROH}+\mathrm{PCl}_5 \rightarrow \mathrm{RCl}+\mathrm{HCl}+\mathrm{B} \end{aligned}$$
The rate of a reaction quadruples when temperature changes from $$27^{\circ} \mathrm{C}$$ to $$57^{\circ} \mathrm{C}$$. Calculate the energy of activation.
Given $$\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}, \log 4=0.6021$$
During the preparation of Mohr's salt solution (Ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of $$\mathrm{Fe}^{2+}$$ ion?
Major products A and B formed in the following reaction sequence, are