\textbf{222-} A silver nitrate solution with a molar mass of 80 g/mol and a concentration of $1.2\ \mathrm{g.mL^{-1}}$ at a certain temperature is prepared. The molar concentration is $2.5\ \mathrm{mol.L^{-1}}$. If at the same temperature the vapor pressure equals $2.5\ \mathrm{mol.L^{-1}}$, how many grams of water are in 100 g of the solution?
\hfill (1)\ 35 \qquad (2)\ 24 \qquad (3)\ 50 \qquad (4)\ 16
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