10% impuritati => puritate de 90%
90/100=mpur/214 => mpur=214*90/100=192,6g Zn
192,6g x=?
Zn + 2HCl -> ZnCl₂ + H₂
65g 2*36,5g
x=192,6*2*36,5/65=216,3g HCl
Aplicam formula concentratiei pentru a afla masa de solutie
c=md*100/ms=> ms=md*100/c=216,3*100/20=1081,5g solutie HCl