Question

a 2.43g sample of MgSO4 hydrate (MGSO4 * x H2O) is heated and 1.19g of anhydrous MGSO4 remains. Calculate the miles of water (x) per 1 mole of MgSO4.

Answer 1

Explanation

Part A: 0.0201

Part B: 2.51g

Part C: 0.1393

Part D: 7:1

Part E: 7

Answer 2

Answer is: ratio of water and magnesium sulfate is 7 : 1.
m(MgSO₄ · xH₂O) = 2,43 g.
m(MgSO₄) = 1,19 g.
m(H₂O) = 2,43 g - 1,19 g.
m(H₂O) = 1,24 g.
n(H₂O) = m(H₂O) ÷ M(H₂O).
n(H₂O) = 1,24 g ÷ 18 g/mol.
n(H₂O) = 0,069 mol.
n(MgSO₄) = m(MgSO₄) ÷ M(MgSO₄).
n(MgSO₄) = 1,19 g ÷ 120,36 g/mol.
n(MgSO₄) = 0,0099 mol.
n(MgSO₄) : n(H₂O) = 0,0099 mol : 0,069 mol.
n(MgSO₄) : n(H₂O) = 1 : 7.