Question

Determine the concentrations of Na2CO3, Na , and CO32– in a solution prepared by dissolving 2.66 × 10–4 g Na2CO3 in 2.25 L of water. Express all three concentrations in molarity. Additionally, express the concentrations of the ionic species in parts per million (ppm). Note: Determine the formal concentration of CO32–. Ignore any reactions with water.

Answer 1

What the question is asking is the molar concentration of the given substance after dilution with the help of values given.The first step of the answer is converting the given weight of Na2CO3 into no of moles.For that we have a formula as,

If the solution is in water and the density of water = 1 g/mL then

1 ppm = 1 μg X / mL solution

Molarity uses moles/L, so the mL need to be converted to L

1 ppm = 1 μg X /( mL solution)x(1 L/1000 mL)
1 ppm = 1000 μg X / L solution
1 ppm = 1 mg X/L solution
We know the molarity of the solution, which is in moles/L. We need to find mg/L. To do this, convert moles to mg.