Chemistry Quiz 8

If solid is more dense than liquid,

there is a positive slope.

If liquid is more dense than solid,

there is a negative slope.

Dissolving an involatile solute in a solvent, what does it do to the vapor pressure of the solvent?

lowers the vapor pressure of the pure solvent

P^o_solvent>P_solution

Dissolving an involatile solute in a solvent, what does it do to the freezing point of the solvent?

Lowers the freezing point of the pure solvent.

T_f (solution) < T_f (solvent)

dTf= T_f (solvent) - T_f (solution)

dTf = i * K_f * m

Dissolving an involatile solute in a solvent, the boiling point of the solution is

greater than the boiling point of the pure solvent.

dTf= T_f (solution) - T_f (solvent)

dTf = i * K_b * m

i = Van’t Hoff factor

= number of solute particles in solution

NaCl → Na + Cl-, i=2

The lower the boiling point.. . .

The more volatile the subtance.

The greater the vapor pressure,

the more volatile the substance.

The lower the moral mass,

the more volatile the substance

Mole fraction

= n_A / (n_A+n_B)

Vapor composition diagram

draw based on amount of gas A vs gas B

Temperature composition diagram

Dew Line is the top. Boiling Line is the bottom.

How to find the boiling range in a temp. composition diagram

boiling range is T of the boiling to T of the dew life for any mole fraction.

Finding mole fraction liq and mole fraction vap of a substance on a composition diagram

The liquid composition is read from the boiling line. The vapor composition from the dew line.

Fractional distillation

A separation process that relies on differences in boiling points of components in a mixture to achieve separation. It involves heating a liquid to create vapor and then condensing the vapor back into liquid to collect the separated components.