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**Solve the following problem:**

Find out the molar mass of the following compounds:

Copper sulphate crystal (CuSO_{4}.5H_{2}O)

(At. mass: Cu = 63.5; S = 32; O = 16; H = 1; Na = 23; C = 12; Fe = 56; N = 14)

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#### Solution

Molar mass of CuSO_{4}.5H_{2}O

= (1 × At. mass Cu) + (1 × At. mass S) + (9 × At. mass O) + (10 × At. mass H)

= (1 × 63.5) + (1 × 32) + (9 × 16) + (10 × 1)

= 63.5 + 32 + 144 + 10

= 249.5 g mol^{–1}

Molar mass of CuSO_{4}.5H_{2}O = **249.5 g mol ^{–1}**

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