2. A gaseous solution was analyzed and found to contain $15 \%$ of $\mathrm{H}_{2}, 10 \%$ of $\mathrm{CO}$, and $75 \%$ of $\mathrm{N}$ by volume. What is the mol fraction and percentage by weight of each gas in the mixture? 3. At $20^{\circ} \mathrm{C}$ diethyl ether exhibits a vapor pressure of $442.2 \mathrm{~mm} \mathrm{Hg}$. At the same temperature 0 solution of a nonvolatile solute in diethyl ether gives a vapor pressure of $413 \mathrm{~mm} \mathrm{Hg}$. Assuming the vapors to behave ideally, find (a) the activity of the solvent in the given solution, and (b) its partial molal free energy of mixing.