Question

Un acid monocarboxilic, aciclic, saturat (A) formeaza o sare pentru care raportul masic C:Na = 24:23 .a) Determinati prin calcul formula moleculara si scrieti formula de structura a acidului (A).
b) Calculati masa solutiei de hidroxid de sodiu , de concentratie procentuala masica 30% , ce reactioneaza stoechiometric cu 2 moli acid (A).

Answer 1

a) C=24/12=2  mol C ||:1 => 2 atomi C

Na=23/23=1 mol Na ||:1 atom Na

Acidul corespunzator a 2 atomi C este acidul acetic => CH3-COOH

CH3-COOH + Na -> CH3-COONa + 1/2H2

b) MCH3-COOH=60g/mol
MNaOH=40g/mol

CH3-COOH + NaOH => CH3-COONa + H2O

1 mol CH3-COOH................................40g NaOH
2 moli CH3-COOH................................x=80g NaOH

C=md/ms*100 => ms=md*100/C=8000/30=266,666g sol. NaOH