A student adds dropwise aqueous ammonia to an aqueous solution containing hexaaquacopper(II) ions until a precipitate forms, and then continues adding excess ammonia until the precipitate completely redissolves. What is the formula of the copper-containing product in the final solution and its visual appearance?
[Cu(NH3)4(H2O)2]2+(aq)[\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+}\text{(aq)}[Cu(NH3)4(H2O)2]2+(aq) and a deep blue solution
[Cu(NH3)6]2+(aq)[\text{Cu}(\text{NH}_3)_6]^{2+}\text{(aq)}[Cu(NH3)6]2+(aq) and a deep blue solution
[Cu(H2O)4(OH)2](s)[\text{Cu}(\text{H}_2\text{O})_4(\text{OH})_2]\text{(s)}[Cu(H2O)4(OH)2](s) and a pale blue precipitate
[Cu(NH3)4(H2O)2]2+(aq)[\text{Cu}(\text{NH}_3)_4(\text{H}_2\text{O})_2]^{2+}\text{(aq)}[Cu(NH3)4(H2O)2]2+(aq) and a pale green solution
41 exam-style questions on OCR GCSE Chemistry Identifying the products of chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.