We prepare an aqueous solution (250ml) of CaCl2 given: concentration of Ca2+ = 0.06 mol\ L

Question

after making the ionization equation of calcium chloride we need to find the concentration of chloride then the entire solution. How?

Answer 1

Ionization equation for calcium chloride:

CaCl₂(aq) ==> Ca²⁺(aq) + 2Cl^-(aq) note: 1 mol CaCl₂ yields 1 mol Ca²⁺ and 2 mol Cl^- ions.

Given a concentration of 0.06 mol/l and 250 ml, we can find the total moles of CaCl₂ present:

250 ml x 1 L/1000 ml = 0.250 L

0.250 L x 0.06 mol/L = 0.015 moles CaCl₂ present

Recall that 1 mol CaCl₂ yields 2 moles of Cl^- ions. Thus, chloride concentration is as follows:

0.015 mol CaCl₂ x 2 mol Cl^- / 1 mol CaCl₂ = 0.03 mol Cl^- ions

[Cl^-] = 0.03 mol/0.25 L = 0.12 mol/L