p= mpur/m impur*100 => m pur=80*20/100=16g CaC2
a) CaC2 + 2H2O = C2H2 + Ca(OH)2
b) MCaC2=ACa+2AC=40+2*12=64g/mol
MC2H2=2AC+2AH+2*12+2*1=26g/mol
64g CaC2............................26g C2H2
16g CaC2............................x=6,5g C2H2
90/100*6,5=5,85g C2H2
HC≡CH + Br2 + H2O = (HO)CH2-CH2Br + HBr
26g C2H2...................160g Br2
5,85g C2H2.................x=36g Br2
C=md/ms*100=>ms=md*100/C=36*100/2=1800g sol Br2
Imi spui daca e bine..