you carry out a titration of a water sample as follows: you measure out 10.0 ml of your water sample into a small flask, then add 1 ml (20 drops) buffer, 4 drops calmagite indicator, and enough water to get the volume of the mixture up to about 20 ml. you titrate this with 0.0115 m edta, using a mini-buret. the buret's initial reading is 2.14 ml, and the final reading is 0.16 ml. what is the water sample's hardness, expressed as moles of dissolved caco3/l?