Răspuns:
p=m,px100/m,i
m,p= 40x65/100g=260g Zn pur
M,Zn=65g/mol
niu=m/M= 260/65mol= 4mol Zn PUR
1mol................................1mol
Zn + 2HCl----> ZnCl2+ H2
4mol.................................x= 4mol H2
pV=niuRT, T= 273+27=300K
2xV= 4x0,082X300---> V=49,2 L H2
Explicație: