quá trình oxi hóa: Mg0 -> Mg2+ + 2e-
quá trình khử: 2H+ + 2e- -> H2 (cần 2 H+ để tạo 1 H2)
----> chỉ cần thêm 2 vào trước HCl (vì H+ là do HCl cung cấp)
----> Mg + 2HCl -> MgCl2 + H2
yay :)
1) in periodic acid (HIO₄), iodine has oxidation number +7, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 4 · (-2) = 0.
x = +7.
2) in molecule of iodine (I₂), iodine has oxidation number 0, because iodine is nonpolar molecule.
3) in sodium iodide (NaI), iodine has oxidation number -1, sodium has oxidation number +1:
+1 + x = 0.
x = -1.
4) in iodic acid (HIO₃), iodine has oxidation number +5, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 3 · (-2) = 0.
x = +5.
