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se introduc 20 grame zinc impur intr-un pahar berzelius in care se gaseste solutie de acid clorhidric si se degaja 0.5 grame hidrogen .calculati : a) puritatea zincului b) masa solutiei de acid clorhidric 9 %


Răspuns :

a)Zn+2HCl=ZnCl2 + H2
puritatea=masa pura*100/masa impura
Masa molara Zn=65g
Masa molara H2=2g
mH2 =0.5
=>65*0.5/2=16.25 g Zn
puritatea=16.25*100/20=81.25
b)Masa molara Hcl=36.5*2=73g
md Hcl=73*0.5/2=18.25
.c=md*100/ms
ms=md*100/c=18.25*100/9=202.77