Which of the following is a non-electrolyte?

If $BaCl_2$ ionizes to an extent of $80 \%$ in aqueous solution,the value of van't Hoff factor is

The freezing point depression of a $0.01 \ m$ aqueous solution of $[Pt(NH_3)_4Cl_4]$ is $0.0054^\circ C$. If $K_f$ for water is $1.80 \ K \ kg \ mol^{-1}$,what is the correct formula for the complex?

Which of the following aqueous solutions has the highest boiling point?

For very dilute solutions of $BaCl_2$ $(t_1)$ and $KCl$ $(t_2)$ having the same molarity,what is the correct relationship between their boiling points?

If the freezing point of a $0.01 \ m$ aqueous solution of a cobalt $(III)$ chloride-ammonia complex (which behaves as a strong electrolyte) is $-0.0558^{\circ} C$,the number of chloride $(Cl^-)$ ions in the coordination sphere of the complex is.
$\left[ K_{f} \text{ of water } = 1.86 \ K \ kg \ mol^{-1} \right]$