Chapter 13 Memory Bank

solute

the substance being dissolved

solvent

the substance doing the dissolving, usually water

solution

solute and solvent together

mass of solution

mass of solute + mass of solvent

% by mass

(mass solute / mass solution) x 100%

ppm

(mass solute / mass solution) x 10^6

molality

m = moles solute / kg solvent

moles from mass

n = mass / molar mass

freezing-point depression

ΔT_f = iK_fm

solution freezing point

T_f,solution = T_f,pure - ΔT_f

boiling-point elevation

ΔT_b = iK_bm

solution boiling point

T_b,solution = T_b,pure + ΔT_b

m

molality; mol solute per kg solvent

n

amount of solute in mol

i

van't Hoff factor; no unit

K_f / K_b

freezing-point and boiling-point constants; °C/m

ΔT_f / ΔT_b

size of freezing-point decrease or boiling-point increase; °C