Magnesium sulfate solution can be made by reacting magnesium oxide with dilute sulfuric acid - Edexcel - GCSE Chemistry - Question 6 - 2013 - Paper 1

To prepare a sample of magnesium sulfate solution, the following steps are carried out:

1. Adding Excess Magnesium Oxide: A measured amount of dilute sulfuric acid is placed in a beaker. Solid magnesium oxide is then gradually added to the acid. The magnesium oxide reacts with the sulfuric acid, producing magnesium sulfate and water.

2. Reaction Completion: The addition of magnesium oxide continues until no further reaction occurs, indicated by the absence of bubbles of gas and the solid no longer dissolving in the acid.

3. Filtration: The mixture is then subjected to filtration to remove any unreacted excess magnesium oxide that did not dissolve. A filter paper is placed in a funnel, and the mixture is poured through it. The solution that passes through will contain pure magnesium sulfate in aqueous form, while the leftover solid stays on the filter paper.