This is the concentrated of the substance expressed in moles per litre, i.e. the number of moles of the solute in 1 litre of solution. Morality is denoted by the letter M.

Molar mass

Molar mass M of a substance is the mass of one mole the substance.

The mole

This is the amount of a substance which contains as many elementary particles as there are carbon atoms in 12g of carbon -12 isotope. The particles can be ions, atoms electrons molecules.

Moles of atoms

 The relative atomic mass (RAM) of an element contains one mole of atoms e.g. 65g of Zn is 1 mole of zinc atoms
Mole = Mass/RAM

The relative molecular mass (RMM) of a compound contains one mole of molecules or ions e.g. 40g of NaOH contains 1 mole of NaOH molecules

Moles = Mass /RMM

If a solution of known concentration is diluted: (concentration x volume of original solution) (concentration x volume of diluted solution).

For calculations using M concentrations:
concentration x volume of acid     = moles of acid
concentration x volume of alkali      poles of lka1i

Concentrations with respect to ions present will depend on the mole ratio of ions present e.g. if we have O.5M sulphuric acid:
H₂SO₄(aq)®2H(aq)+SO (aq)

The solution is 0.5 M with respect to SO ions The solutions is (0.5 x 2) = 1M with respect to H⁺ ions.