Question

A 7.41 mass % aqueous solution of sodium chloride has a density of 1.14 g/mL. Calculate the molarity of the solution. Give your answer to 2 decimal places.

Answer 1

Molarity for solution is 1.44 M

Step-by-step explanation:

Molarity = Mol of solute / 1L of solution

We would need the volume of solution (To be calculated with density)

We would need the moles of solute (To be calculated with mass and molar mass of solute)

7.41 % by mass means 7.41 g of solute in 100 g of solution

So, moles of solute → 7.41 g / 58.45 g/mol = 0.127 mol

Let's determine the volume by density

Density = Mass / volume

1.14 g/mL = 100 g / Volume

Volume = 100 g / 1.14 g/mL → 87.7 mL

To reach molarity we must have the volume in L

87.7 mL . 1L / 1000 mL = 0.0877 L

Molarity → mol /L = 0.127 mol / 0.0877L → 1.44 M