Question

In qualitative analysis, in III group $NH _4 Cl$ is added before $NH _4 OH$ because

• A. to increase the concentration of $NH _4{ }^{+}$ions
• B. to increase concentration of $Cl ^{-}$ions
• C. to reduce the concentration of $OH ^{-}$ions
• D. to increase concentration of $OH ^{-}$ions

Answer 1

Answer: (C)

Due to common ion effect addition of $NH _4 Cl$ in group (III) suppresses the ionisation of $NH _4 OH$ with the result, concentration of $OH ^{-}$decreases.