How can I find out the mass measurement?

Your question reads like a laboratory experiment assignment. I assume your chem lab has a balance of some kind for measuring mass.

There are tables where you can probably look up the density of CuSO4 solutions of various concentration.

Then the 1% (by mass) CuSO4 is added to the water, the volume will increase somewhat, but I have no way of knowing how much without making the measurement or using previous measurements by someone else, which might be available online or in a chemistry handbook.