Here's how to determine the copper-to-sulfate ratio in copper(I) sulfate:

1. Chemical Formula:

* Copper(I) sulfate has the chemical formula Cu₂SO₄.

2. Subscripts:

* The subscripts in the formula tell us the ratio of atoms:

* 2 copper (Cu) atoms

* 1 sulfate (SO₄) group

3. Copper-to-Sulfate Ratio:

* Therefore, the copper-to-sulfate ratio in copper(I) sulfate is 2:1.

In other words, for every 2 copper atoms, there is 1 sulfate group.