Answer to Question #56284 in General Chemistry for Emily

Question

How many equivalents of chloride ion are in 20.0 mL of a 2.0 M solution of CaCl2 and how do you calculate this?

Answer 1

Solution

СаCl₂ in aqueous solution dissociates according to the equation:
СаCl₂ = Ca²⁺ + 2Cl^–
Thus, 1 molecule СаCl₂ forms a 2 ion Cl^–
1 liter (1000 ml) of 2.0 M solution СаCl₂ contains 2 mol СаCl₂
20.0 ml of 2.0 M solution СаCl₂ contain 2*20/1000 mol = 0.04 mol СаCl₂.
From 0,04 mol СаCl₂ formed 2*0,04 = 0,08 equivalent of the chloride ions

Answer: Formed 0.08 per equivalent of chloride ions