Cu (II) sulfate exists as a hydrate. It has many practical uses including use as a fungicide and pesticide. When mixed with chromium and arsenic it forms the wood preservative called CCA. CCA was used in pressure treated wood to protect wood from rotting due to insects and microbial agents. Because CCA treated wood contains toxic heavy metals, its use has been discontinued for home use and children’s play sets. 1. A chemist is given a sample of the CuSO4 hydrate and asked to determine the empirical formula of it. The original sample weighed 42.75 g. After heating to remove the waters of hydration, the sample weighed 27.38 g. Determine the formula for this hydrate.