The temperature in a surface condenser is \(40^{\circ} \mathrm{C}\) and the vacuum is \(69 \mathrm{~cm}\) of \(\mathrm{Hg}\) while the barometer reads \(75 \mathrm{~cm}\) of \(\mathrm{Hg}\). Determine the partial pressure of steam and air and the mass of air present per \(\mathrm{kg}\) of steam.