Risep
Ar O = 16 ya bukan 18 jadi Mr CaCO₃ = 100 g/mol
CaCO₃ 20% = 20 gram CaCO₃ dalam 100 gram larutan massa CaCO₃ = 20 gram massa air = 100 - 20 = 80 gram n CaCO₃ = gr/Mr = 20/100 = 0,2 mol n air = gr/Mr = 80/18 = 4,44 mol n total = 0,2 + 4,44 = 4,64 mol
a) molalitas m = n CaCO₃ x (1000/P) m = 0,2 x (1000/80) = 2,5 m
b) Fraksi mol CaCO₃ Xt = n CaCO₃ / n total Xt = 0,2/4,64 = 0,0431
c) Molaritas larutan massa larutan = 100 gram ρ = 1,2 g/mL maka V larutan = massa larutan/ρ = 100/1,2 = 83,3 mL = 0,0833 L M = n CaCO₃ / V larutan M = 0,2/0,0833 = 2,4 M
jadi Mr CaCO₃ = 100 g/mol
CaCO₃ 20% = 20 gram CaCO₃ dalam 100 gram larutan
massa CaCO₃ = 20 gram
massa air = 100 - 20 = 80 gram
n CaCO₃ = gr/Mr = 20/100 = 0,2 mol
n air = gr/Mr = 80/18 = 4,44 mol
n total = 0,2 + 4,44 = 4,64 mol
a) molalitas
m = n CaCO₃ x (1000/P)
m = 0,2 x (1000/80) = 2,5 m
b) Fraksi mol CaCO₃
Xt = n CaCO₃ / n total
Xt = 0,2/4,64 = 0,0431
c) Molaritas larutan
massa larutan = 100 gram
ρ = 1,2 g/mL
maka
V larutan = massa larutan/ρ = 100/1,2 = 83,3 mL = 0,0833 L
M = n CaCO₃ / V larutan
M = 0,2/0,0833 = 2,4 M