Question

Which of the following ionic substances will be most effective in precipitating the sulphur sol?

• A. $KCl$
• B. $Ba{Cl}_2$
• C. ${Fe}_2{\left({SO}_4\right)}_3$
• D. ${Na}_3{PO}_4$

Answer 1

The correct option is C ${Fe}_2{\left({SO}_4\right)}_3$

Higher is the charge on cation, higher is the precipitating power.

${Fe}_2{\left({SO}_4\right)}_3$ will be most effective in precipitating the sulphur sol. Sulphur sol is negatively charged colloid. It will be precipitated by cations.

Among the given ionic substances, $F{e}^{3+}$ ion has maximum charge and hence maximum precipitating power.

Hence, option $C$ is correct.