Odpowiedzi

2010-04-12T18:20:35+02:00
A)
Szukane:
Vr=?
Dane:
Cmol=3mol/dm3
nNaOH=10moli

Cmol=n/Vr, czyli Vr= n/Cmol
Vr=10moli/3mol/dm3=3,3dm3


b)
Szukane:
Vr=?
Cmol=2mol/dm3
mK₂CO₃ =100g

MK₂CO₃=2*39g/mol+12g/mol+3*16g/mol=138g/mol

n=m/M
nK₂CO₃=100g/ 138g/mol=0,72mole

Cmol=n/Vr, czyli Vr= n/Cmol
Vr=0,72mole/ 2mol/dm3=0,36dm3

2010-04-12T18:26:33+02:00
Wzór:
Cm=n÷v /*v
Cm*v=n /÷ Cm
v=n÷Cm

a)
Cm= 3mol/dm³
n=10moli
v=?

v=10mol÷3mol/dm³
v=3.33dm³

b)
Cm=2mol/dm3
m=100g
v=?

M K₂CO₃ = 2×39+12+16×3=78+12+48=138g/mol

138g - 1mol
100g - xmol

x=100×1/÷138
x=0,7mol

v=0,7mol÷2mol/dm³
v=0,35dm³