Raspuns: msNaCO=40g
Explicație:C= md/ms•100 md=ms•C/100=20•49/100=9,8g
M NaOH=40g/mol
M H2SO4=98g/mol
2NaOH + H2SO4 → Na2SO4 + 2H2O
2•40g NaOH.............98gH2SO4
md g NaOH...............,.9,8gH2SO4
=> md= 80•9,8/98=8
C= md/ms•100=>ms=md•100/C=8•100/10=80gNaOH.
