Question

34.8 g of Na₂O are used to form a solution with a volume of 450.0 mL L. What is the

molarity?
34.89

Answer 1

1.25 M

Step-by-step explanation:

(Step 1)

Convert grams to moles using the molar mass of Na₂O.

Atomic Mass (Na): 22.990 g/mol

Atomic Mass (O): 15.999 g/mol

Molar Mass (Na₂O): 2(22.990 g/mol) + 15.999 g/mol

Molar Mass (Na₂O): 61.979 g/mol

34.8 g Na₂O 1 mole
---------------------- x --------------------- = 0.561 moles Na₂O
61.979 g

(Step 2)

Convert milliliters to liters.

1,000 mL = 1 L

450.0 mL 1 L
------------------ x ------------------- = 0.4500 L
1,000 mL

(Step 3)

Calculate the molarity using the molarity ratio.

Molarity = moles / volume (L)

Molairty = 0.561 moles / 0.4500 L

Molarity = 1.25 M