Question

34.8 g of Na₂O are used to form a solution with a volume of 0.50 L. What is the molarity?

Answer 1

Molarity = 1.12 mol/L

Step-by-step explanation:

To make an aqueous solution of Na₂O, the concentration will be calculated by: concentration (c) (or molarity) = number of moles present (n) ÷ volume needed (V) (in litres)

since we don't have moles, we can calculate moles by:

number of moles (n) = mass present (m) (in grams) ÷ molar mass (M) (in grams per mole), which we can find using a standard IUPAC Periodic Table

∴ n(Na₂O) = m/M = 34.8/(22.99×2+16.00) = 0.56147 mol

Now we have the number of moles present, we can calculate concentration:

∴ c(Na₂O) = n/V = 0.56147/0.50L = 1.12 mol/L