Calculate the vapor pressure at 50°c of a coolant solution that is 54.0: 46.0 ethylene glycol-to-water by volume. at 50.0°c, the density of water is 0.9880 g/ml, and its vapor pressure is 92 torr. the vapor pressure of ethylene glycol is less than 1 torr at 50.0°c.

Missing question: The liquid used in automobile cooling systems is prepared by dissolving ethylene glycol (HOCH2CH2OH) in water. Ethylene glycol has a molar mass of 62.07 g/mol and a density of 1.115 g/mL at 50.0°C.
If we use 100 mL of solution:
V(ethylene glycol - C₂H₆O₂) = 0,54 · 100 mL = 54 mL.
V(water) = 0,46 · 100 mL = 46 mL.
m(C₂H₆O₂) = 54 mL · 1,115 g/mL = 60,21 g.
n(C₂H₆O₂) = 60,21 g ÷ 62,07 g/mol = 0,97 mol.
m(H₂O) = 46 mL · 0,988 g/mL = 45,45 g.
n(H₂O)  = 45,45 g ÷ 18 g/mol = 2,525 mol.
mole fraction of solvent: 2,525 mol / (2,525 mol + 0,97 mol) =0,722.
Raoult's Law: p(solution) = mole fraction of solvent · p(solvent).
p(solution) = 0,722 · 92 torr = 66,42 tor.

Density and pressure