Why halogens can't exhibit the +2 oxidation state?
All the elements of halogen family exhibit -1 oxidation state. However elements such as chlorine, bromine and iodine also show +1, +3, +5 and +7 state. This higher oxidation state of chlorine, bromine and iodine is realized when these halogens are in combination with small and highly electronegative atoms of fluorine and oxygen. The oxides and oxoacids of chlorine and bromine have +4 and +6 states. There are no valence shell d orbitals in fluorine atom and therefore it cannot expand its octet. Fluorine being the most electronegative element exhibits only -1 oxidation state.
Halogens are highly reactive, they react with metals and non-metals in order to form halides. Their reactivity decreases as we move down the group. Halogens have strong oxidizing properties. F2 is the strongest oxidizing halogen. It easily oxidizes other halide ions present in solution or in the solid phase. In general, a halogen oxidizes halide ion which is of higher atomic number. For example:
F2+2X−→2F−+X2(X=Cl, Br or l)
From standard electrode potential, the decreasing oxidizing ability of halogen can be easily observed.
The relative oxidizing nature of halogens can be illustrated by their reactions with water. Fluorine oxidizes water to oxygen. Whereas chlorine and bromine react with water in order to form respective hydrohalic and hypohalous acids. Iodine reacts with water in a non-spontaneous way. I– can be oxidized by water in the acidic medium. For example:
4l−(aq)+4H+(aq)+O2(g)→1l2(s)+2
All the elements of halogen family exhibit -1 oxidation state. However elements such as chlorine, bromine and iodine also show +1, +3, +5 and +7 state. This higher oxidation state of chlorine, bromine and iodine is realized when these halogens are in combination with small and highly electronegative atoms of fluorine and oxygen. The oxides and oxoacids of chlorine and bromine have +4 and +6 states. There are no valence shell d orbitals in fluorine atom and therefore it cannot expand its octet. Fluorine being the most electronegative element exhibits only -1 oxidation state.
Halogens are highly reactive, they react with metals and non-metals in order to form halides. Their reactivity decreases as we move down the group. Halogens have strong oxidizing properties. F2 is the strongest oxidizing halogen. It easily oxidizes other halide ions present in solution or in the solid phase. In general, a halogen oxidizes halide ion which is of higher atomic number. For example:
F2+2X−→2F−+X2(X=Cl, Br or l)
From standard electrode potential, the decreasing oxidizing ability of halogen can be easily observed.
The relative oxidizing nature of halogens can be illustrated by their reactions with water. Fluorine oxidizes water to oxygen. Whereas chlorine and bromine react with water in order to form respective hydrohalic and hypohalous acids. Iodine reacts with water in a non-spontaneous way. I– can be oxidized by water in the acidic medium. For example:
4l−(aq)+4H+(aq)+O2(g)→1l2(s)+2
