You don't say if the solute is volatile or non-volatile. I assume it is volatile. Since X is used for mole fraction, I will change the unknown compound to Y.
mols Y = 2/32 = ?
mols CS2 = 100/76 = ?
total molsl = ? + ? = ?
Then XCS2 = mols CS2/total mols = ?
XY</sub) = mols Y/total mols = ?
The pressure due to CS2 is
pCS2 = XCS2 * PoCS2 = ?
Total Psolution = 848.9
pY = 848.9-pCS2
Finally,
pY = Xy*PoY
Solve for Y po (vapor pressure Y). look it up in tables to find the compound. Post your work if you get stuck.
The vapour pressure of solution having 2 grams of solute X (molar mass-32) in 100 grans of CS2 (vapour pressure-854 torr) is 848.9 torr. The molecular formula of the solute is ?
1 answer
1 answer