In analytical chemistry, hydrated ammonium iron(II) sulfate (commonly known as Mohr's salt) is widely used as a primary standard in redox titrations because of its stability against oxidation in air.
What is the relative formula mass (MrM_rMr) of Mohr's salt, (NH4)2Fe(SO4)2⋅6H2O(\text{NH}_4)_2\text{Fe}(\text{SO}_4)_2 \cdot 6\text{H}_2\text{O}(NH4)2Fe(SO4)2⋅6H2O?
Relative atomic masses (ArA_rAr):
284.0284.0284.0
312.0312.0312.0
378.0378.0378.0
392.0392.0392.0
53 exam-style questions on AQA GCSE Chemistry 3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations, covering 3.1.1 Conservation of mass and balanced chemical equations, 3.1.2 Relative formula mass, 3.1.3 Mass changes when a reactant or product is a gas, and 3.1.4 Chemical measurements. Each one has a worked solution and a mark scheme showing where the marks go.