Răspuns:
-CALCULEZ moli H2
niu=V/Vm= 8,96/22,4 mol=0,4molH2
-deduc, din ecuatia chimica, moli Zn
1mol...................................1mol
Zn + 2HCl------> ZnCl2 + H2
x.........................................0,4mol
x=niu= 0,4molZn
m= niuxM=0,4x65g=26gZn pur
calculez masa de Zn impur,din purutate p= m,px100/.m,i
m,i= 26x100/26g=100g Zn impur
impuritati=m,impura-m,pur=100-26=> 74g
Explicație: