Question

Calculate the molarity of 10.6% w/v of Na2Co3 solution.

Answer 1

Explanation:

Molarity can be found with this formula:

molarity=number of moles/volume (L)

We know the volume, which is

500mL = 0.5 L.

We still need to know the number of moles, though, but we can find that from its mass.

10.6 g of Na2CO3 is:

10.6g molar mass=10.6g/106 g/mol=0.1 mol

Now, we can just plug those values in to solve for molarity:

molarity=0.1 mol/0.5 L=0.2 M

Answer 2

Answer:

The molarity of 10% w/v of Na₂CO₃ solution is equal to one Molar.

Explanation:

Given: 10.6%w/v of sodium carbonate solution means 10.6g of Na₂CO₃ present in 100ml of solution.

Mass of solute (Na₂CO₃) $=10.6g$

Volume of the solution $=100ml=0.1L$

Molar mass of  Na₂CO₃ $=23*2+12+3*16=106gmol^{-1}$

Number of moles, Na₂CO₃ = mass/molar mass

                                            $=\frac{10.6}{106}=0.1mol$

Molarity =  (moles of  Na₂CO₃)/(volume of solution in L)

Molarity of  Na₂CO₃ solution $=\frac{0.1}{0.1}=1M$

Therefore, the molarity of  Na₂CO₃ solution is  1M.