Question

A solution is prepared by dissolving 10.6 g sodium carbonate in enough water to produce

500.0 mL solution. What is the molarity of sodium carbonate in the solution?

Answer 1

0.2mol/dm³

Step-by-step explanation:

Given parameters:

Mass of Na₂CO₃ = 10.6g

Volume of solution = 500mL

Unknown:

Molarity of solution = ?

Solution:

The molarity of a solution can be determined using the expression below:

Molarity =
`(number of moles )/(volume)`

Number of moles =
`(mass)/(molar mass)`

Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol

Number of moles =
`(10.6)/(106)` = 0.1mol

Convert mL to dm³;

500mL will give 500 x 10⁻³dm³or 0.5dm³

So;

Molarity =
`(0.1)/(0.5)` = 0.2mol/dm³