Answer:
Vapor pressure of solution is 78.2 Torr
Explanation:
This is solved by vapor pressure lowering:
ΔP = P° . Xm . i
Vapor pressure of pure solvent (P°) - vapor pressure of solution = P° . Xm . i
NaCl → Na⁺ + Cl⁻ i = 2
Let's determine the Xm (mole fraction) These are the moles of solute / total moles.
Total moles = moles of solvent + moles of solute
Total moles = 0.897 mol + 0.182 mol → 1.079 mol
0.182 / 1.079 = 0.168
Now we replace on the main formula:
118.1° Torr - P' = 118.1° Torr . 0.168 . 2
P' = - (118.1° Torr . 0.168 . 2 - 118.1 Torr)
P' = 78.2 Torr
