An iron nail is placed in a solution of blue copper(II) sulfate. Over time, a brown solid appears and the solution becomes colourless. This is because copper and a solution of iron(II) sulfate forms.

Add between 1.30 g and 1.50 g of hydrated iron(II) sulfate crystals, FeSO 4 ·xH 2 O. Reweigh the evaporating basin, and record the new mass in the results table. Place the evaporating basin ...