Solution Composition Equations

Question 1

Mass percent (%)

Answer 1

> percent by mass of the solute in a solution

= mass of solute/mass of solution * 100
= mass A/(mass A + mass B) * 100

Question 2

Mole Fraction (mol)

Answer 2

> useful for predicting solutions’ VAPOUR PRESSURE

= moles A/(moles of A + … + moles of n)

Question 3

Molarity (M)

Answer 3

> commonly used to describe a [] of a solute in a solution

= mol of solute/L of solution

Question 4

Molality (m)

Answer 4

= mol of solute/kg of solvent

>convert L into kg via density

Question 5

Parts per million (ppm)

Answer 5

> used for dilute solution

= mg of solute/kg of solution

Question 6

Normality (N)

Answer 6

= n of equivalents/L of solution
> in acid-base reactions, 1 equivalent = amount of acid or base needed to donate or accept 1 mole of protons (1 mole of H+)
> in redox reactions, 1 equivalent = amount of reactant needed to donate or accept 1 mole of electrons