Question

10 g of a sample of water contained 16.2 g of Ca(HCO3), its
hardness is​

Answer 1

Answer:

16.2 g of calcium hydrogen carbonate are present in 10

5

g of water.

Hence, the concentration of calcium hydrogen carbonate in ppm is

total mass of solution

mass of solute

×10

6

=

10

5

16.2

×10

6

=162 ppm.

Also, the hardness is expressed in terms of calcium carbonate.

1 gm mole or 162 g of calcium hydrogen carbonate ≡ 1 gm mole or 100 g of calcium carbonate.

162 ppm of calcium hydrogen carbonate ≡ 100 ppm of calcium carbonate.

Hence, the hardness of solution is 100 ppm.