Molarity converstions with ions

Question

A student prepares a solution by placing 0.387 g of NiSO4 · 6H2O and 0.123 g of NiCl2 · 6H2O in a 250-mL volumetric flask. A small amount of distilled water is then added, and the compounds are swirled in the flask until they dissolve. After they have dissolved, the solution is diluted to the mark. What is the molar concentration of Cl− ions in the final solution? Answer in units of M.

also how to find molar concentration of N(+2)

Answer 1

NiSO₄ = Ni²⁺ + SO₄^2-

moles NiSO4•6H2O = 0.387 g x 1 mol/262.9 g = 0.001472 moles = 0.001472 moles Ni²⁺

NiCl2 = Ni²⁺ + 2Cl^-

moles NiCl2 = 0.123 g x 1 mol/237.7g = 0.0005175 moles = 0.0005175 mol Ni²⁺ & 0.001035 mol Cl-

Total moles Ni²⁺ = 0.001472 + 0.0005175 = 0.001990 moles

Final [Ni²⁺] = 0.001990 mol/ 0.250 L = 0.007958 M = 0.00796 M

Final [Cl-] = 0.001035 mol/0.250 L = 0.00414 M