Add 15.55 g of platinum to a beaker then add 200 mL of conc. HCl and 25 mL of conc. nitric acid, place a RBF with ice water on top of the beaker, start heating the acid solution. Every 4 h add additional 25 mL of conc. nitric acid until all of the platinum dissolves. Then with heating concentrate the solution to less than 100 mL and cool down to room temperature, then add 100 mL of conc. HCl, boil until no brown gas is present. Add another 100 mL of conc. HCl and repeat. Boil down to 50 mL and remove the residual water with vacuum desiccator.
Pt + 4 HNO3 + 6 HCl → H2PtCl6 + 4 NO2 + 4 H2O
Platinum is slowly reacting with the acids when heated
All of the platinum has reacted
Boil down to 100ml
100ml of HCl was added twice with boiling
The pure chloroplatinic acid crystals