Copper(II) sulfate is , with copper formally in oxidation state +2. Hydrated crystals include water of crystallization, so the hydrate must be specified when converting a weighed mass into a chemical amount.
In the catalysed peroxide comparison, dissolved copper sulfate is treated with sodium hydroxide to form a precipitate. That experiment tests the resulting solid-forming treatment; it does not establish identical catalytic behaviour for every dissolved copper species.
[ref]
Chemistry 2e by Paul Flowers and others. Chemical equations, oxidation-state conventions and solution equilibria; chapters4,14–17
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