Question

a solution contains 0.400 g of naoh in 20.0 ml of solution. what is its molarity?

Answer 1

Molar mass NaOH = 40.0 g/mol

number of moles : 0.400 / 40.0 = 0.01 moles

20.0 mL in liters = 20.0 / 1000 = 0.02 L

M = n / V

M = 0.01 / 0.02

= 0.5 M