Answer:
CuSO₄ · 3H₂O
Step-by-step explanation:
Sulfate, SO₄²⁻, has a charge of -2, while copper(I) has a charge of +1. For the charges to cancel and produce a neutral salt, there must be two copper(I) ions for every sulfate.
The copper(I) sulfate salt may absorb water from its environment to produce a hydrate. The water molecules can usually be removed from the salt by heating and are not bonded directly to the copper(I) ion, but instead are included in the lattice structure of the salt.
The number of water molecules per unit of the salt is indicated and written after the formula for the salt, separated by a dot.
The formula CuSO₄(H₂O)₃ indicates that the water is bonded directly to the copper(I) and is not a hydrate.