Question

300g solutie de acid clorhidric de concentratie 36.5% reactioneaza cu zinc.Considerand ca reactia este totala, calculati:
a) Cati moli de zinc se consuma in aceasta reactie
b) Cate grame de sare se obtin in urma reactiei
c) Ce volum de hidrogen se degaja in urma reactiei

Answer 1

ms = 300g sol. HCl
C = 36,5%

Zn + 2HCl => ZnCl2 + H2

C = md/ms*100 => md = C*ms/100 = 36,5*300/100 = 109,5g HCl

MHCl = 36,5g/mol

n = m/M = 109,5/36,5 = 3 moli HCl

a) 1 mol Zn...............2 moli HCl
x moli Zn...................3 moli HCl

x = 1,5 moli Zn

b) 2 moli HCl....................136g ZnCl2
3 moli HCl..........................xg ZnCl2
x = 204g ZnCl2

c) n Zn = n H2 = 1,5 moli

n = V/Vm => V =n*Vm = 1,5*22,4 = 33,6 L H2