If x is the mole fraction pentane, 1-x is the mole fraction of hexane.
Assume a mole-fraction-weighted vapor pressure for the mixture.
425x + 151(1-x) = 241
274 x = 90
Solve for x
What is the mole fraction of hexane? (Assume ideal behavior.)
Assume a mole-fraction-weighted vapor pressure for the mixture.
425x + 151(1-x) = 241
274 x = 90
Solve for x
The vapor pressure of the solution is given as 241 torr, which is the sum of the partial pressures of pentane and hexane:
P_solution = P_pentane + P_hexane
Given that the vapor pressures of pentane (P_pentane) and hexane (P_hexane) are 425 torr and 151 torr, respectively, at room temperature, we can rewrite the equation as follows:
241 torr = (mole fraction of pentane) * 425 torr + (mole fraction of hexane) * 151 torr
Let's assume x represents the mole fraction of hexane in the solution. The mole fraction of pentane can be expressed as (1 - x) since the sum of the mole fractions must be 1.
Plugging these values into the equation, we have:
241 torr = (1 - x) * 425 torr + x * 151 torr
Simplifying the equation:
241 torr = 425 torr - 425x + 151x
Combining like terms:
241 torr - 425 torr = -274 torr = -274x
Dividing both sides by -274 torr:
x = 0.9993
Therefore, the mole fraction of hexane in the solution is approximately 0.9993.