What is the molarity of sodium chloride in solution that is 13.0% by mass sodium chloride and that has a density of 1.10 g/mL?

molarity: 2.4 M

Explanation:

1. Suppose you have 100 mL de solution:

Use density to find grams of soluton:

100 mL solution x (1.10 g / 1 mL) = 110 g solution

2. FInd the amount of sodium chloride pure:

110 g solution x (13 g NaCl / 100 g solution) = 14.3 g NaCl

3. Change grams to mol:

14.3 g NaCl x (1 mol NaCl / 58.44 g NaCl) = 0.24 mol NaCl

4. Molarity:

M = mol NaCl / L solution

M = 0.24 mol NaCl / 0.1 L = 2.4 M