Question

A `5*g` mass of sodium chloride, and an `8.2*g` mass of sodium sulfate are dissolved in a `200*mL` of aqueous solution. What is `[Na^+]`?

Answer 1

Well I make `[Na^+]=1.00*mol*L^-1`

Explanation:

`"Moles of NaCl"=(5.0*g)/(58.44*g*mol^-1)=0.0856*mol`.

`"Moles of"` `Na_2SO_4=(8.2*g)/(142.04*g*mol^-1)=0.0577*mol`.

And thus `[Na^+]=(0.0856*mol+2xx0.0577*mol)/(200*mLxx10^-3*L*mL^-1)`

`=??*mol*L^-1`.

Why did I double the molar quantity with respect to `Na_2SO_4`. Did I make a mistake?