Density of CuSO4?

A. The "official" density of copper sulphate [on eBay or Amazon]depends on the type you are talking about. Simple CuSO4 has a density of 3.605g/cc, but basic copper sulphate (CuSO4.3H2O) has 3.78. However, pentahydrate (CuSO4.5H2O) has 2.284. These are rather different to your 1.112g/cc. Think about how you did the measurement - did you simply fill a known volume with copper sulphate crystals and weigh it; if so, think about how well packed the crystals are. For instance, will there be spaces between the crystals (clue: think about ball bearings in a jar).

Try dissolving a known weight of copper sulphate in water and seeing how much the volume increases (if at all) and try to understand what is going on. If you want to easily measure the density of the pentahydrate, grow a large crystal of it and weigh it; then do a water displacement experiment, but remember it will dissolve in water, so be quick! It is very easy to grow copper sulphate pentahydrate crystals as big a 4-5 cms long, but it will take quite a long time (a matter of weeks). The crystals are very pretty with a well defined shape, but it is not so easy to grow the other forms.

Have fun with science and remember, there is no "wrong" answer when trying to understand science. The beauty about science is that it is the gaining of knowledge - if the experimental answer is incorrect, then it is not the science that is wrong, it is the experiment and you have learnt what NOT to do. You can then go back and think up a different experiment that will give you the right answer and you will have gained all that extra knowledge - this is called research, where there is no wrong answer!

A. The density of 100% pure copper sulphate solution of concentration 1M should be approximately 1.2 g/ml. It may range between 1.18 to 1.2. This is determined experimentally.
Your copper sulphate sample's purity dictates the concentration so be sure to calculate the purity of copper sulphate by dissolving 1 mol of copper sulphate weight (that is ~160 g for anhydrate and ~250 g for pentahydrate) and dissolve in water to form 1M solution