Question

Calculate the molarity of a solution prepared by dissolving 11.5 g naoh in enough water to make 1.5 l of solution.

Answer 1

Molar mass NaOH = 39.997 g/mol

Number of moles :

n = mass of solute / molar mass

n = 11.5 / 39.997

n = 0.287 moles

Therefore :

Molarity = moles solute / volume 

Molarity = 0.287 / 1.5 => 0.1913 M