Question

What does the 'concentration of a solution' mean?

Answer 1

Molarity:

• “Molarity (M) is defined as the number of moles of solute dissolved in one liter (or one cubic decimetre) of solution.”

Molality:

• “Molality (m) is defined as the number of moles of the solute per kilogram (kg) of the solvent.”

The concentration of a solution:

• “The composition of a solution can be described by expressing its concentration”.
• The concentration of the solution can be determined quantitatively in several ways.

1. Mass percentage (w/w):

• The mass percentage of a component of a solution is defined as:

$\mathrm{Mass}\%\mathrm{of}\mathrm{the}\mathrm{component}=\frac{\mathrm{Mass}\mathrm{of}\mathrm{the}\mathrm{component}\mathrm{in}\mathrm{the}\mathrm{solution}}{\mathrm{Total}\mathrm{mass}\mathrm{of}\mathrm{the}\mathrm{solution}}\times 100$

2. Volume percentage (V/V):

• The volume percentage is defined as:

$\mathrm{Volume}\%\mathrm{of}\mathrm{the}\mathrm{component}=\frac{\mathrm{Volume}\mathrm{of}\mathrm{the}\mathrm{component}}{\mathrm{Total}\mathrm{volume}\mathrm{of}\mathrm{solution}}\times 100$