Q No 1 Calculate the % of pure Almunium in 10 kg of aluminium oxide(AL2O3) OF 90% purity Q - Chemistry -

Question

Q No 1 Calculate the % of pure Almunium in 10 kg of aluminium
oxide(AL​2O3) OF 90% purity
Q 2 Hydrated CaSO​4 xH2O contains 21%
of water of crystallisation Calculate the no of molecules(x) of
water of crystallisation

Geetha · Accepted Answer

a
 Molecular mass of Al2O3 = (2 × 27) + (3 × 16) = 102 gIn 102 g of Al2O3 amount of  Al =54 gFor 10000 g of Al2O3 amount of Al = 54102 × 10000 = 5294
12 g% of Al in 10000 g Al2O3 = 5294
1210000 × 100 = 52
94 %If the oxide is of 90 % purity, Al % = 52
94100 × 90 =47 65 % b
 Mass of CaSO4 
xH2O  = 100 gMass of H2O = 21 gMass of CaSO4 = 79 gMoles of water = 2118 = 1
17Moles of CaSO4 = 79136 = 0
5801Simple ratio of water : CaSO4 = 1
170 5801 : 0 58010 5801 = 2
02 : 1 ≃ 2 : 1Thus the water of crystallisation is 2 and the formula = CaSO4
 2 H2O

Q No.1. Calculate the % of pure Almunium in 10 kg of aluminium oxide(AL​2O3) OF 90% purity Q.2 Hydrated CaSO​4.xH2O contains 21% of water of crystallisation. Calculate the no of molecules(x) of water of crystallisation

Q No.1. Calculate the % of pure Almunium in 10 kg of aluminium oxide(AL₂O₃) OF 90% purity
Q.2 Hydrated CaSO₄.xH₂O contains 21% of water of crystallisation. Calculate the no of molecules(x) of water of crystallisation