Question 55
Making copper sulfate: add black copper oxide to about 100 cm³ dilute sulfuric acid in a 250 cm³ beaker. Heat very gently while stirring; do not boil the acid. Turn off heat when the solution is blue and let it cool. Filter, transfer the filtrate to an evaporating basin, warm gently until crystals start at the edge, then leave for days to crystallise. The hot solution can spit and burn. Plan the equipment and risks, then carry out the method under teacher supervision.
