Question

0.2 mol of HCl and 0.1 mol of barium chloride were dissolved in water to produce a 500 $mL$ solution.The molarity of the CI is

• A. 0.06M
• B. 0.09M
• C. 0.12M
• D. 0.80M

Answer 1

The correct option is D 0.80M

Explanation:

=> First of all lets calculate the total number of CL- ions.

=> One mol of HCL will give one mol of H+ and one mol of CL- when dissociates. Thus, .2 mol gives .2 mol CL-

=> One mol of Bacl2 will give one mole of ba2+ and 2 mol of CL- when dissociates. Hence, 0.1 mol will give .2 mole CL-

=> So the total mols of CL- are .2+.2 = .4

=> Molarity:

molarity M = Total moles of solute/ Volume of solution in liter.

= .4/.5 = 0.8 M

Therefore, the molarity of CL- in solution is 0.8 M.