Question

If 1000g of a water sample contains 10g of CaCO3 then the hardness of that water sample is

Answer 1

To calculate this you'll need this:

500mg = 0.5g

1L water = 1000mL = 1000g (Density of water is 1g/1mL)

(0.5g CaCO3/1000g water + 0.5g CaCO3) x 1,000,000 = 500ppm

Think about 1mg of solute dissolved in 1 kg of solvent.

This would be 0.001g/1000g = 1ppm