Answer:
1. Formulae of hydrate is Na₂CO₃.10H₂O
2. Formulae of hydrate is CaSO₄.2H₂O
Explanation:
Q1. Mass of hydrated salt = 8.50 g mass
mass of anhydrous salt = 7.26 grams
mass of water lost = 1.24
Formula of hydrated salt = Na₂CO₃.xH₂O
Formula of anhydrous salt = Na₂CO₃
Molar mass of anhydrous salt is obtained as below where Na = 23, C = 12, O = 16, H = 1
Molar mass of Na₂CO₃ = (23 *2 + 12 + 16 * 3) = 106 g
molar mass of water = (1 *2 + 16) = 18 g
Mole ratio of Na₂CO₃ to H₂O = 7.26/106 : 1.24/18
Mole ratio of Na₂CO₃ to H₂O = 0.0068 : 0.068
Mole ratio of Na₂CO₃ to H₂O = 1 :10
Therefore, formulae of hydrate is Na₂CO₃.10H₂O
Q2. Mass of hydrated salt = 60.98 g mass
mass of anhydrous salt = 48.23 grams
mass of water lost = 12.75
Formula of hydrated salt = CaSO₄.xH₂O
Formula of anhydrous salt = CaSO₄
Molar mass of anhydrous salt is obtained as below where Ca = 40, S = 32, O = 16, H = 1
Molar mass of CaSO₄= (40 + 32 + 16 * 4) = 136 g
molar mass of water = (1 *2 + 16) = 18 g
Mole ratio of CaSO₄ to H₂O = 48.23/136 : 12.75/18
Mole ratio of CaSO₄ to H₂O = 0.35 : 0.70
Mole ratio of CaSO₄ to H₂O = 1 : 2
Therefore, formulae of hydrate is CaSO₄.2H₂O
