Question

Va rog sa ma ajutati cu aceasta problema!!!
se pun X g de zinc in 25g solutie de HCl de concentratie 36,5%. Dupa terminarea reactiei, raman 10 g Zn nereactionat. Aflati x. Va rog cu rezolvare completa!!!

Answer 1

md HCl/ m sol = 36.5/100
md HCl / 25 = 36.5/100
md HCl = 36.5 × 25/100
nr de moli = m / 36.5 = 0.25 moli

1...........2
Zn + 2HCl = ZnCl2 + H2
x..........0.25

x = 0.25/2 = 0.125 moli
masa Zn = 65 × 0.125 = 8.125 g
masa totala Zn = 10 + 8.125 = 18.125