Atoms, molecules and stoichiometry: compare question

Hydrated iron(II) sulfate, $\ce{FeSO4.7H2O}$, is a pale green crystalline solid. On strong heating it changes to anhydrous iron(II) sulfate, a white solid. Both solids dissolve in water to give the same pale green solution.

Compare the hydrated salt with the anhydrous salt. In your answer include:

• the meaning of the terms hydrated, anhydrous and water of crystallisation;
• a balanced equation, with state symbols, for the change on heating;
• an explanation of why $\ce{FeSO4}$ is described as an empirical formula rather than a molecular formula;
• the ionic equation, excluding spectator ions and with state symbols, for the reaction of either salt with aqueous sodium hydroxide, and why the two salts give the same ionic equation.