Question

Problema clasa a 8-a: 980 g sol. H2SO4 10% + sol. NaOH 10 %
? g sol. NaOH 10%
? g, moli Na2SO4

sol.=solutie

Answer 1

2NaOH+H2SO4----------->Na2SO4+2H2O

md=ms*c/100
 mdH2SO4=980*10/100=98 g

din ec. reactiei :
2*40 g NaOH.........98 g H2SO4..........142 g Na2SO4 ===>

==>   mNaOH=80 g (md)   atunci ms=md*100/c=80*100/10=800 g sol. NaOH
 
mNa2SO4=142 g ==>  n=m/M=142g/142g/mol= 1 mol  Na2SO4