[kerilynn]

If 15.55 g NaOH are dissolved in enough water to make a 500.0 mL solution, what is the molarity of the solution?

[Jasmine]

Hi Keri,

Molarity is defined as Moles solute per Liter of Solution.

1 Mole of NaOH weighs 40.01 grams (23.0 g Na + 16.0 g O + 1.008 g H)

15.55 grams NaOH X (1 mole NaOH/ 40.01 grams NaOH) = 0.389 moles NaOH

500.0 mL X (1.0 Liter/1,000 mL) = 0.500L solution

0.389 moles NaOH/0.500L solution = 0.780M solution