An industrial chemist reacts a waste sample of solid aluminium turnings with an excess of dilute hydrochloric acid.
Which of the following represents the correct net ionic equation for this reaction, along with the correct physical observations?
2Al(s)+6H+(aq)→2Al3+(aq)+3H2(g)2Al(s) + 6H^+(aq) \rightarrow 2Al^{3+}(aq) + 3H_2(g)2Al(s)+6H+(aq)→2Al3+(aq)+3H2(g) with effervescence and the solid dissolving to form a colourless solution.
Al(s)+3H+(aq)→Al3+(aq)+3H(g)Al(s) + 3H^+(aq) \rightarrow Al^{3+}(aq) + 3H(g)Al(s)+3H+(aq)→Al3+(aq)+3H(g) with a pungent smelling gas and a yellow solution.
Al(s)+2H+(aq)→Al2+(aq)+H2(g)Al(s) + 2H^+(aq) \rightarrow Al^{2+}(aq) + H_2(g)Al(s)+2H+(aq)→Al2+(aq)+H2(g) with effervescence and a green precipitate.
2Al(s)+6H+(aq)+6Cl−(aq)→2AlCl3(aq)+3H2(g)2Al(s) + 6H^+(aq) + 6Cl^-(aq) \rightarrow 2AlCl_3(aq) + 3H_2(g)2Al(s)+6H+(aq)+6Cl−(aq)→2AlCl3(aq)+3H2(g) with the formation of a white precipitate of aluminium chloride.
276 exam-style questions on Edexcel GCSE Chemistry 4.1 Acids, covering 4.1.1 Acids, alkalis and the pH scale, 4.1.2 Hydrogen ion concentration and pH, 4.1.3 Dilute and concentrated, weak and strong acids, 4.1.4 Bases, alkalis and the reactions of acids, 4.1.5 Chemical tests for hydrogen and carbon dioxide, 4.1.6 Neutralisation as a reaction of acids with bases, 4.1.7 Preparing soluble salts, and 4.1.8 Solubility rules and preparing insoluble salts. Each one has a worked solution and a mark scheme showing where the marks go.