Question
Calculate the quantity of lime required to soften 60000 litres of well water containing 16.2 g of calcium carbonate per hundred litre.
Solution
Balanced equation is
Ca(HCO3)2 + Ca(OH)2
2CaCO3 +2H2O
(40+2+24+96) (40+32+2)
= 162 g = 74 g
16.2 g ?
(i) To calculate the weight of calcium bicarbonate present.
Weight of calcium bicarbonate present in 100 litres of well water = 16.2 g, Now 100 L well water contains
= 16.2 g Ca(HCO3)2
60000 L well water contains
(ii) To calculate the quantity of lime required. Stoichiometry indicates that 162 g Ca(HCO3)2 requires 74 g Ca(OH)2
Ca(HCO3)2 + Ca(OH)2
2CaCO3 +2H2O(40+2+24+96) (40+32+2)
= 162 g = 74 g
16.2 g ?
(i) To calculate the weight of calcium bicarbonate present.
Weight of calcium bicarbonate present in 100 litres of well water = 16.2 g, Now 100 L well water contains
= 16.2 g Ca(HCO3)2
60000 L well water contains(ii) To calculate the quantity of lime required. Stoichiometry indicates that 162 g Ca(HCO3)2 requires 74 g Ca(OH)2
