Hitunglah massa NaOH yg terdapat di dlm 500 ml larutan NaOH 20%.jika massa jenis larutan dianggap = 1g/ml!

M= p × 10 × % / Mr
M= 1 × 10 × 20% / 40
M= 5M

n= M × V
n= 5M × 0,5 L
n= 2,5 mmol

m= n × Mr
m= 2,5 mmol × 40gr/mol
m= 100 gram

Fast but need to concern
M= p × 10 × % / Mr
n/ V = p × 10 × % / Mr
m/ (Mr × V) = p × 10 × % / Mr
m = p × 10 × % × Mr × V / Mr
m = p × 10 × % × V
m = 1 × 10 × 20 × 0,5 L
m = 100 gram