Answer to Question #107306 in General Chemistry for Zac

Question

In a reaction to determine the calcium content of hard water, a student reacts 50ml of a mono- protic acid (HCl) with 20 mls of water. What is the concentration of Calcium ions in the water if all the calcium reacts with the acid?

Answer 1

Ca(HCO₃)₂ + 2 HCl = CaCl₂ + 2H₂O + 2 CO₂

C(Ca²⁺) = 50 × (2 × C_HCl / 20) = 5 × C_HCl

Answer: 5C_HCl.