REAGENTS
4.—4.1 Hydrochloric acid solution 50% (V/V): dilute an appropriate volume of hydrochloric acid (d = 1.18 g/ml) with an equal volume of water.
4.2 Hydrochloric acid, N solution (approximately).
4.3 Hydrochloric acid, 0.5 N solution.
4.4 Magnesium solution: dissolve 1.013 g magnesium sulphate (MgSO4.7H2O) in 0.5 N hydrochloric acid solution (4.3) and dilute to 100 ml with this acid.
1 ml of this solution contains 1 mg of magnesium (Mg).
or
weigh out 1.658 g of magnesium oxide, previously calcined at 600°C for 2 hours, place in a beaker with 100 ml of water and 120 ml of approximately N hydrochloric acid (4.2). After dissolution, transfer quantitatively into a one litre graduated flask, make up the volume with water and mix.
1 ml of this solution contains 1 mg of magnesium (Mg).
4.5 Strontium chloride solution: dissolve 75 g strontium chloride (SrCl2.6H2O) in 0.5 N hydrochloric acid solution (4.3) and dilute to 500 ml with this acid.