How many grams of solid NaOH are required to prepare 500 ml of a 0.04 M solution? (b) Express the concentration of this solution in terms of N, g/liter, % w/v?

Answer 1

Na = 23 g/mol
O = 16 g/mol
H = 1 g/mol
so NaOH = 40 g/mol
need (500 / 1000) * 0.04 moles
so
0.02 * 40 = 0.80 grams for half a liter

Answer 2

it is clearly

Answer 3

80