35. Solution to Chemistry Problem

4. An indicator in an ammonia buffer medium for titration of an aliquot volume of hard water of 50.00 ml in the presence of arsenazo I, 15.00 ml of 0.0100 m EDTA were consumed. It is for such an aliquot in excess NaOH for titration in the presence of added and indicator calcein that 10.00 ml of 0.0100 m EDTA were consumed. Calculate: a) the molar concentration of magnesium and calcium ions in water; b) the total hardness expressed as CaCO3 (mg/l),