1)
a)c/100=md/ms => md=c*ms/100=98*760/100=744,8g H2SO4
b)cand adaugam apa, se modifica doar masa solutiei
notam cu X masa apei adaugate
md=mdfinal si msf=ms+X
38/100=744,8/(760+X) => 760+X=744,8*100/38=1960 => X=1200g apa
2)
40g..................58,5g
NaOH + HCl -> NaCl + H2O
20g..................x=?
x=29,25g NaCl