1.27 carry out mole calculations using volumes and molar concentrations.

CALCULATING MOLES:

- To calculate moles using volumes and molar concentrations, you simply do:

- Moles = Concentration x Volume.

An example from (http://www.docbrown.info/page04/4_73calcs11msc.htm)
What mass of sodium hydroxide (NaOH) is needed to make up 500 cm³ (0.500 dm³) of a 0.500 mol dm^-3 (0.5M) solution? [A_r's: Na = 23, O = 16, H = 1]
- 1 mole of NaOH = 23 + 16 + 1 = 40g
- molarity = moles / volume, so mol needed = molarity x volume in dm³
- 500 cm³ = 500/1000 = 0.50 dm³
- mol NaOH needed = 0.500 x 0.500 = 0.250 mol NaOH
- therefore mass = mol x formula mass
- = 0.25 x 40 = 10g NaOH required