Question

Un amestec de NaOH si KOH in raport molar 1:2 cantareste 15,2 g. Afla volumul solutiei de H2SO4 1M necesar neutralizării amestecului

Answer 1

x/y=1/2==>y=2x

MNaOH=40g/mol
MKOH=56g/mol

40x+56y=15.2 ==> 40x+56*2x=15.2==>152x=15.2==>x=0.1 moli
y=2x ==>y=0.2 moli

2mol........1mol
2NaOH + H2SO4 --> Na2SO4 + 2H2O
0.1mol.......x=0.05mol

2mol.......1mol
2KOH + H2SO4 --> K2SO4 + 2H2O
0.2mol....x=0.1mol

In total sunt necesari ==> 0.1moli + 0.05 moli =0.15 moli 

Cm=n/Vs==> Vs=n/Cm=0.15/1=0.15L=150cm³ H2SO4