Question

determine how much CuSO4-5H2O is required to prepare a 50ml solution of 0.0200M CuSO4

Answer 1

Answer -

Note - formula of a given salt is CuSO₄⋅5H₂O, so its a hydrate. You must include the waters of hydration when calculating the formula weights.

Molar mass of CuSO₄⋅5H₂O:

63.54 (Cu) + 32.06 (S) + 4 × 15.99 (O) + 5 × [2 × 1.01 (H) + 15.99 (O)] = 249.68 g mol^-1

Therefore ,

For 1000 ml of 1M need 249.68 gm of CuSO₄⋅5H₂O

For 100 ml of 1 M need 24.968 gm of CuSO₄⋅5H₂O

For 50 ml of 1 M need 12.484 gm of CuSO₄⋅5H₂O

Therefore, for 50 ml of 0.020 M need x gm of CuSO₄⋅5H₂O

x = 12.484 x 0.020

x = 0.249 gm

Therrefore, 0.249 g of CuSO4 . 5H2O to make 50 mL of 0.020 M CuSO4