Answer to Question #171734 in Physical Chemistry for Akshat

Question

Calculate the amount of lime (74% pure) and soda (95% pure) for the treatment of 70,000 L of water, whose analysis report is as follows: Ca(HCO3)2 = 40.5 ppm, Mg(HCO3)2 = 39 ppm, MgSO4 = 30 ppm, CaSO4 = 34 ppm, CaCl2 = 27.75ppm, KNO3 = 3 ppm, NaCl = 10 ppm. Also, calculate the temporary and permanent hardness of the water sample in terms of CaCO3 equiv.

Answer 1

As mentioned, the degree of hardness is expressed as parts per million (ppm) and thus may be defined as the number of parts by weight of CaCO3 (equivalent to Mg salts) present in a million (106) parts by weight of water. It is given that 1 kg of water contains 24 mg of MgSO4.