Question

Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution. The density of the solution is 1.53 g/mL. Calculate the molarity of this sodium hydroxide solution. Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution. The density of the solution is 1.53 g/mL. Calculate the molarity of this sodium hydroxide solution. 0.450 M 25.0 M 125. M 19.1 M

Answer 1

[NaOH] = 19.1 M

Last option.

Step-by-step explanation:

Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution.

50% by weight means, that in 100 g of solution we have 50 grams of solute.

Molar mass of solute: 40 g/m

Mass / Molar mass = moles

50 g / 40 g/m = 1.25 moles

These are the moles of solute in 100 grams of solution, so we must use density data, so we can find out our volume.

Solution density = Solution mass / Solution volume

1.53 g/mL = 100 g / Solution volume

Solution volume = 100 g / 1.53 g/mL

Solution volume = 65.3 mL

1.25 moles of solute are in 65.3 mL of solution

Molarity = moles /L

Let's convert 65.3 mL in L

65.3 / 1000 = 0.0653 L

1.25 moles /0.0653 L = 19.1 M