I.
1.
I II VII II IV II
H2S ; Cl2O7 ; SO4
2.
0 +1 -2 +7 -2
S ; H2S ; Cl2O7
II.
Cl2 + H2 --> 2HCl
HCl + NaOH --> NaCl + H2O
2NaCl + H2SO4 --> Na2SO4 + 2HCl
III.
3 moli V L
Na2S + 2HCl --> 2NaCl + H2S
1 22,4
=> V = 3x22,4/1 = 67,2 L H2S
