Question

Why mohr salt is diluted with sulphuric acid?

Answer 1

Ferrous ions of Mohr's salt undergo hydrolysis in aqueous solution. To prevent the hydrolysis, Conc. H2SO4 needs to be added to the Mohr's salt crystals during the preparation of its standard solution. Another reason is also to prevent the oxidation of Fe2+ ions of Mohr's salt to Fe3+ ions.