Answer:
[NaOH] = 19.1 M
Last option.
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
