\(AgCl _{(s)} \rightarrow Ag _{(\text {(aq) }}^{+}+ Cl _{(\text {(qq) })}^{-}\)
Solubility of \(AgCl =\left[ Ag ^{+}\right]=\left[ Cl ^{-}\right]\)
\(\left[ Ag ^{+}\right]=\left[ Cl ^{-}\right]= S\)
Solubility(s) product,
\begin{aligned}
& K _{\phi p}=\left[ Ag ^{+}\right]\left[ Cl ^{-}\right] \\
& K _{\phi p}=S \times S=S^{2} \\
&S=1.30 \times 10^{-5} moldm ^{-3} \\
& K _{\phi p}=\left(1.30 \times 10^{-5}\right)^{2} \\
&=1.65 \times 10^{-10} mol ^{2} dm ^{-6}
\end{aligned}