naoh merupakan basa kuat yang digunakan sebagai bahan pembuat sabun jika terdapat larutan naoh 2M sebanyak 200 ml. jika diketahui mr naoh 40gr/mol serta massa j

M = 2 M
V = 200 mL = 0,2 L
Mr = 40
mj = 1,2 gram/mL

n NaOH = M × V
= 2 M × 0,2 L
= 0,4 mol

m NaOH = n × Mr
= 0,4 mol × 40
= 16 gram

m lar = mj × V
= 1,2 gr / mL × 200 mL
= 240 gram

m air = m lar - m NaOH
= 240 gram - 16 gram
= 224 gram

Kemolalan NaOH
m = n NaOH × ( 1000 / m air )
m = 0,4 mol × ( 1000 / 224 gr )
m = 1,786 molal