Answer:
molarity of Cl⁻ ions = 5.0 M
Step-by-step explanation:
The molarity of a solution expresses the amount in moles of a solution present in a litre of solvent. Its unit is mol/L or mol/dm³ written as M.
MgCl₂ when dissolved to form an aqueous solution dissociates into positive and negative ions, Mg²⁺and Cl⁻ ions.
Equation of the dissociation of MgCl₂ in aqueous solution is given below:
MgCl₂(aq) -----> Mg²⁺(aq) + 2Cl⁻(aq)
1 mole of aqueous MgCl₂ produces 2 moles of chloride ions, Cl⁻
Molar concentration of MgCl₂(aq) = 2.5 M
Molarity of chloride ions = number of moles of Cl⁻ ions * molarity of MgCl₂
molarity of Cl⁻ ions = 2 * 2.5 M
molarity of Cl⁻ ions = 5.0 M