Answer:
69.79 mmHg is the pressure for the solution
Explanation:
Formula for vapor pressure lowering:
Vapor pressure of pure solvent(P°) - Vapor pressure of solution (P') = P° . Xm
Xm → Molar fraction of solute (moles of solute / Total moles)
Total moles = Moles of solute + Moles of solvent
Let's determine the moles:
50.36 g . 1mol/342 g = 0.147 moles of sugar
88.69 g. 1mol/ 18g = 4.93 moles of water
Total moles = 0.147 + 4.93 = 5.077 moles
Xm = 0.147 / 5.077 = 0.0289
If we replace data given in the formula:
71.88 mHg - P' = 71.88 mmHg . 0.0289 . 0.0289
P' = - (71.88 mmHg . 0.0289 - 71.88 mmHg)
P' = 69.79 mmHg