Question

In the detection of III group basic radicals, ${NH4OH}$ is added after ${NH_4Cl}$ to

• A. increase the ionisation of $\ce{NH_4OH}$
• B. increase the ionisation of salt solution
• C. decrease the ionisation of salt solution
• D. decrease the ionisation of $\ce{NH4OH}$

Answer 1

Answer: (D)

decrease the ionisation of $\ce{NH4OH}$

Answer 2

${NH4OH}$ suppresses the degree of dissociation of ${NH_4Cl}$ hence the concentration of ${OH^-}$ ions in the solution decreases appreciably. Due to this, only group Ill hydroxides are precipitated having low solubility product.