Question

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

Answer 1

Answer:

0.2mol/dm³

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 = $\frac{number of moles }{volume}$  

     Number of moles  = $\frac{mass}{molar mass}$  

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

   Number of moles  = $\frac{10.6}{106}$   = 0.1mol

   Convert mL to dm³;

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

So;

Molarity  = $\frac{0.1}{0.5}$    = 0.2mol/dm³