Discuss the different methods of preparation and properties of dioxygen.

Explanation

Preparation : Dioxygen can be prepared in laboratory by following methods :
i) By thermal decomposition of oxides of metals.
`2Ag_(2)O (s) rarr 4 Ag (s) + O_(2) (g), 2PbO_(2)(s) rarr 2PbO(s) + O_2 (g)`
ii) Decomposition of hydrogen peroxide into water and dioxygen.
`2H_(2)O_2 (aq) overset(MnO_(2))rarr 2H_(2)O_(l) + O_(2)(g)`
Properties of dioxygen i) Dioxygen combines with metals and non metals to form oxides. For example,
`2Ca + O_(2) rarr 2CaO, 4Na + O_(2) 2Na_(2)O , C + O_(2) rarr CO_(2)`
ii) Dioxygen is paramagnetic in nature as it has two unpaired electrons.
iii) The bond dissociation enthalpy of O = O is very high.