Question

One brand of laundry bleach is an aqueous solution containing 4.00% sodium hypochlorite (NaOCl) by mass. You may want to reference (Pages 552 - 557) Section 13.5 while completing this problem. Part A What is the molarity of this solution

Answer 1

Answer:

molarity of the solution = 0.548 mol/L

Note: Additional information about the question is given as follows;

One brand of laundry bleach is an aqueous solution containing 4.00% sodium hypochlorite (NaOCl) by mass

What is the molarity of this solution? (Assume a density of 1.02 g/mL .)

Explanation:

A 4.00 percentage by mass composition of sodium hypochlorite (NaOCl) solution means that 100 g of the solution contains 4.00 g NaOCl.

Thus, a 1000 g of the solution contains 40.0 g NaOCl

Density of solution = 1.02 g/mL

Therefore, the volume occupied by 1000 g solution = mass/density

volume of 1000 g solution = 1000 g/1.02 g/ml = 980.4 mL

Molar mass of NaOCl = 74.5 g/mol

Number of moles = mass/molar mass

Number of moles of NaOCl = 40.0 g/74.5 g/mol

Number of moles of NaOCl  = 0.537 mole

Therefore, molarity = number of moles / volume(L)

volume of solution in litres = 980.4/1000 = 0.9804 L

Molarity = 0.537/0.9804 = 0.548 mol/L

Therefore, molarity of the solution = 0.548 mol/L