An ammonium ion has the formula NH4+\text{NH}_4^+NH4+.
A sulfate ion has the formula SO42−\text{SO}_4^{2-}SO42−.
Which of the following is the correct formula for ammonium sulfate?
NH4SO4\text{NH}_4\text{SO}_4NH4SO4
(NH4)2SO4(\text{NH}_4)_2\text{SO}_4(NH4)2SO4
NH4(SO4)2\text{NH}_4(\text{SO}_4)_2NH4(SO4)2
(NH4)2(SO4)2(\text{NH}_4)_2(\text{SO}_4)_2(NH4)2(SO4)2
183 exam-style questions on Edexcel GCSE Chemistry 1.1 Formulae, equations and hazards, covering 1.1.1 Formulae, word and balanced equations, 1.1.2 Balanced ionic equations, and 1.1.3 Hazard symbols and risk in practical work. Each one has a worked solution and a mark scheme showing where the marks go.