Which of the following solutions will have the highest concentration of chloride ions?
a)0.10 m nacl
b)0.10 m alcl3
c)0.10 m mgcl2
d)0.05 m cacl2
e)all of these solutions have the same concentration of chloride ions.

B = 0.10 M of AlCl₃

Explanation:

A = 0.10 M NaCl

NaCl → Na⁺ + Cl⁻

sodium chloride dissociate into sodium and chlorine ions. The one mole of NaCl produced on mole of Na⁺ and one mole of Cl⁻, so concentration of chloride ions will be 0.10 M.

B = 0.10 M of AlCl₃

AlCl₃  →    Al³⁺ + 3Cl⁻

AlCl₃ dissociate into aluminium cation and chlorine anion. one mole of AlCl₃ dissociate into one mole of Al³⁺ and three mole of Cl⁻.

so concentration of chloride ion in 0.10 M solution is

0.10 × 3 = 0.3 M

C = 0.10 M MgCl₂

MgCl₂   → Mg²⁺ +  2Cl⁻

MgCl₂ dissociate into one mole of Mg²⁺ and two mole of Cl⁻.

so concentration of chloride ions in 0.10 M solution of MgCl₂ is,

2× 0.10 M = 0.20 M

d = 0.05 M CaCl₂  

CaCl₂  →   Ca²⁺ +  2Cl⁻

CaCl₂ dissociate into one mole of  Ca²⁺ and two mole of Cl⁻, So concentration of chloride ions in 0.05 M CaCl₂ is

2× 0.05 = 0.1 M