d=ms/Vs => ms=d*Vs=1,14*490=558,6g solutie H2SO4
20% din 558,6=20*558,6/100=111,72g H2SO4
80g...........98g...........142g.........36g
2NaOH + H2SO4 -> Na2SO4 + 2H2O
91,2g........111,72g....161,88g....41,04g
solutia finala: mapa din cele doua solutii + mapa de pe reactie + msare
solutia de NaOH are c=20% => ms=5md=5*91,2=456g solutie NaOH
m1apa=456-91,2=364,8g apa
m2apa=558,6-111,72=446,88g apa
mapa|reactie=41,04g
mNa2SO4=161,88g
msfinala=1014,6g solutie
cf=161,88*100/1014,6=15,95%