Question

0.4 moles of hcl and 0.2 moles of cacl2 were dissolved in water ro have 500 ml solution the molarity of cl-ion is

Answer 1

Answer:

0.016 M

Explanation:

HCl dissociates in aqueous solution as follows:

HCl ⇒ H⁺ + Cl⁻

1 mole of HCl produces 1 mole of Cl⁻

⇒0.4 moles of HCl produces 0.4 moles of Cl⁻       ---------------------- (1)

CaCl₂ dissociates as follows:

CaCl₂⇒ Ca²⁺ + 2Cl⁻

1 mole of CaCl₂ produces 2 moles of Cl⁻

⇒0.2 mole of CaCl₂ produces 2 x 0.2 = 0.4 moles of Cl⁻     ---------------(2)

From (1) and (2)

Total moles of Cl⁻  produced = 0.4 moles + 0.4 moles

                                                = 0.8 moles

Volume of solution = 500 ml = 0.5 Liter

                           

Molarity = Number of moles of solute/Volume of solution

              = 0.8/50

              = 0.016 M