A $100-\mathrm{m}^{3}$ storage tank with fuel gases is at $20^{\circ} \mathrm{C}, 100 \mathrm{kPa}$ containing a mixture of acetylene $\left(\mathrm{C}_{2} \mathrm{H}_{2}\right),$ propane $\left(\mathrm{C}_{3} \mathrm{H}_{8}\right),$ and butane $\left(\mathrm{C}_{4} \mathrm{H}_{10}\right) . \mathrm{A}$
test shows that the partial pressure of the $\mathrm{C}_{2} \mathrm{H}_{2}$ is $15 \mathrm{kPa}$ and that of the $\mathrm{C}_{3} \mathrm{H}_{8}$ is $65 \mathrm{kPa}$. How much mass is there of each component?