When CuSO4.5H2O is heated it loses the 5 molecules of water as they are present as water of crytstallisation.
CuSO4.5H2O →CuSO4 + 5H2O
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These water molecules lost combines with blue coloured copper chloride and turns to pale pink.
CoCl2 + 6H2O →CoCl2.6H2O
(Blue) (Pale Pink)
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Thus X is CuSO4 and Y is H2O.
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