Question

Which of the following electrolyte will be most effective in coagulation of gold sol ?

• A. $NaN{O}_3$
• B. $K_4\left[Fe\right(CN{)}_6]$
• C. $N{a}_{3}P{O}_4$
• D. $MgC{l}_2$

Answer 1

The correct option is D $MgC{l}_2$

As $MgC{l}_2$ gives highest cation concentration with maximum positive charge ( =$+2$ on cation) , it will bring about the coagulation of a gold sol quickest and in the least of concentration.