Transition and InnerTransition Elements - Result Question 69
69. Write the balanced chemical equations for the following reactions.
(i) A mixture of potassium dichromate and sodium chloride is heated with concentrated $\mathrm{H}_2 \mathrm{SO}_4$.
(ii) Potassium permanganate is added to a hot solution of manganese sulphate.
$(1990,2\ \text{M})$
Show Answer
Solution:
(i) $$ \begin{alignedat} \mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7+4 \mathrm{NaCl}+6 \mathrm{H}_2 \mathrm{SO}_4 \longrightarrow & 2 \mathrm{CrCl}_3+3 \mathrm{Cl}_2 \uparrow+2 \mathrm{KHSO}_4+4 \mathrm{NaHSO}_4 \\
- & 4 \mathrm{NaHSO}_4 + 3 \mathrm{H}_2 \mathrm{O} + 2 \mathrm{KHSO}_4 \end{aligned} $$
(ii) $$ \begin{alignedat} 2 \mathrm{KMnO}_4+3 \mathrm{MnSO}_4+2 \mathrm{H}_2 \mathrm{O} \longrightarrow 5 \mathrm{MnO}_2+\mathrm{K}_2 \mathrm{SO}_4+5 \mathrm{H}_2 \mathrm{SO}_4\ \\
- & \mathrm{K}_2 \mathrm{SO}_4+2 \mathrm{H}_2 \mathrm{SO}_4 \end{aligned} $$
BETA
