Between `BaCl_(2)` or KCl which one is more effective for the coagulation of a negatively charged sol?

Explanation

According to Hardy-Schulze rule, a sol is coagulated by an ion whose charge is opposite to that of the sol, and the higher the charge of the ion, the greater its efficiency for coagulation. Since a `Ba2^(+)` ion has twice as much charge as a `K^(+)` ion, it will show greater efficiency for coagulating a negatively charged sol.