A \( 42.12\% \) (\( \text{w/v} \)) solution of \( \mathrm{NaCl} \) causes precipitation of a certain sol in \( 10 \) hours. The coagulating value of \( \mathrm{NaCl} \) for the sol is:
[Given: Molar mass : \( \mathrm{Na} = 23.0 \, \text{g mol}^{-1} \); \( \mathrm{Cl} = 35.5 \, \text{g mol}^{-1} \).]