Answer:
56.4 mmHg
Explanation:
Given:
Vapor pressure of the solution, P solution = 55 mmHg
The mass of sucrose (C₆H₁₂O₆) = 10 g
Also, Molar mass of sucrose (C₆H₁₂O₆) = 180 g/mol
So, moles = Given mass/ molar mass
Hence, moles of sucrose in the solution = 10 g / 180 g/mol = 0.05556 mol
Given that: Mass of ethanol = 100 g
Molar mass of ethanol = 46 g/mol
Hence, moles of ethanol = 100 g / 46 g/mol = 2.174 mol
Mole fraction of solvent, ethanol is:
X ethanol = 2.174 mol / (2.174 + 0.05556) mol = 0.975
Applying Raoult's Law
P solution = X ethanol*P° ethanol
<u>
=> P° ethanol = P solution / X ethanol = 55 mmHg / 0.975 = 56.4 mm Hg</u>
