Question

Which impurities are removed by the following reagents:

(c) Potassium hydroxide solution

Answer 1

• Potassium hydroxide solution is used to remove sulphur dioxide.
• When potassium hydroxide is passed over sulphur dioxide it forms potassium sulphite.

$\underset{\mathrm{Sulphur}\mathrm{dioxide}}{{\mathrm{SO}}_2}+\underset{\mathrm{Potassium}\mathrm{hydroxide}}{2\mathrm{KOH}}\to \underset{\mathrm{Potassium}\mathrm{sulphite}}{{\mathrm{K}}_2{\mathrm{SO}}_3}+{\mathrm{H}}_2\mathrm{O}$

Potassium hydroxide: It is an inorganic compound, it's chemical formula is $\mathrm{KOH}$. It is also known as lye and is commonly referred to as caustic potash.