When draining 100 ml of a 10% solution of calcium chloride (density 1.11 g / ml) and 106 g of a 20% solution of sodium carbonate

bystudin | November 11, 2020 | Education

When draining 100 ml of a 10% solution of calcium chloride (density 1.11 g / ml) and 106 g of a 20% solution of sodium carbonate, a precipitate formed. Calculate the mass of the sediment.

CaCl2 + Na2CO3 → CaCO3 ↓ + 2NaCl
n (CaCL2) = (100 x 0.1 x 1.11) / (40 + 71) = 0.1 mol – deficient
m (Na2CO3 substance) = 106 x 0.2 = 21.2 g
n (Na2CO3) = 21.2 / (46 + 12 + 48) = 21.2 / 106 = 0.2 mol – in excess
⇒ n (CaCO3) = 0.1 mol
m (CaCO3) = 0.1 x (40 + 12 + 48) = 10 g
Answer: the mass of the sediment (calcium carbonate) is 10 g.

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