3.2.ReagentsU.K.
(a)Sulphuric acid, 75 ± 2 % m/mU.K.
Prepare by adding carefully, while cooling, 700 ml of sulphuric acid (relative density at 20 °C: 1,84) to 350 ml of distilled water.
After the solution has cooled to room temperature, dilute to 1 litre with water.
(b)Ammonia, dilute solutionU.K.
Dilute 80 ml of ammonia solution (relative density at 20 °C: 0,880) to 1 litre with water.