Help with Ionic Concentrations?

[Droolv]

Hey guys, I'm doing some revision for my Chem assessment and I'm having difficulties with questions revolving around ionic concentrations. I've posted a photo with the question and possible answers. I'd love some help, thanks in advance.

The question reads: a solution is made by dissolving 0.1mol of sodium chloride, and 0.1mol of calcium chloride in water to make a volume of 200ml of solution. What are the ionic concentrations, in molL^-1, of this solution?

[RuiAce]

Hey guys, I'm doing some revision for my Chem assessment and I'm having difficulties with questions revolving around ionic concentrations. I've posted a photo with the question and possible answers. I'd love some help, thanks in advance.

The question reads: a solution is made by dissolving 0.1mol of sodium chloride, and 0.1mol of calcium chloride in water to make a volume of 200ml of solution. What are the ionic concentrations, in molL^-1, of this solution?

(Image removed from quote.)

In 0.1 mol of NaCl there is exactly 0.1 mol of Na⁺, and 0.1 mol of Cl^-

Using the formula C=n/V we therefore have

[Na⁺] = n_Na⁺/V = 0.1/0.2 = 0.5 mol L^-1

In 0,1 mol of CaCl₂ there is exactly 0.1 mol of Ca²⁺, and 0.2 mol of Cl^-

So we have [Ca²⁺] = n_Ca²⁺/V = 0.1/0.2 = 0.5 mol L^-1

Our total moles of the chloride ion, however, is
n_Cl^- = 0.1 + 0.2 = 0.3 mol

Hence [Cl^-] = 0.3/0.2 = 1.5 mol L^-1

[Droolv]

Thanks so much!