Paragraph 3 REAGENTS

Analytical-grade chromium VI oxide; Cr^VIO₃

Sulfuric acid diluted to 60% by volume: pour 360 ml of water into a one litre beaker and carefully add 640 ml of sulfuric acid, density at 20°C ρ = 1.83 g/ml.

Silver nitrate: 0.1 M solution.

Barium hydroxide: weigh out 15 grams of barium hydroxide (Ba(OH)₂.8H₂O), and dissolve completely in hot water. Allow to cool and transfer to a one-litre flask. Fill up to the mark and mix. Filter through a pleated filter paper.

Hydrochloric acid: 0.1 M standard solution.

Sodium hydroxide: 0.1 M standard solution.

Bromophenol blue: solution of 0.4 grams per litre in water.

Phenolphthalein: solution of 2 grams per litre in 60% by volume ethanol.

Soda lime: particle dimensions, about 1.0 to 1.6 mm.

Demineralised water, freshly boiled to remove carbon dioxide.