Answer:
0.2990
Explanation:
All liquids intend to vaporize independent of the temperature if the pressure is higher enough. This pressure is called the vapor pressure. When it occurs, the liquid and the vapor phases will be in equilibrium, and so the fractions of the components of the liquids and the vapor can be calculated.
The molar fraction of the liquid (x) can be calculated by the composition, so, calling xc for cyclohexane, and ca for acetone:
xc = 1.90/(1.90 + 2.60) = 0.4222
xa = 1 - 0.4222 = 0.5778
The total pressure of the system (P) can be calculated by Dalton's Law:
P = Pc + Pa
Where Pc and Pa are the partial pressures of the components. The partial pressures can be calculated by the Raoult's Law:
Pc = xc*P°c
Pa = xa*P°a
Where P° is the vapor pressure, so:
P = xc*P°c + xa*P°a
P = 0.4222*97.6 + 0.5778*229.5
P = 137.8 torr
The molar fraction at the vapor phase (y) is the partial pressure divided by the total pressure:
yc = Pc/P
yc = (xc*P°c)/P
yc = (0.4222*97.6)/137.8
yc = 0.2990
Explanation:
a) 3 sig. figures
b) 3 sig. figures
c) 6 sig. figures
d) 2 sig. figures
e) 1.09 × 104 = 113.36 = 5 sig. figures
if it is 1.09 × 10^4, it is 10900 = 3 sig. figures
f) 4 sig. figures
