Question
Discuss the consequences of high enthalpy of H – H bond in terms of chemical reactivity of dihydrogen.
Solution
The H-H bond dissociation enthalpy is the highest for a single bond between two atoms of any element.This influences the chemical behaviour of dihydrogen. It is inert at room temperature with many metals and non-metals. However, at high temperature or in the presence of the catalyst, it combines with metals and non-metals to form hydrides.
Since its orbital is incomplete with 1s electronic configuration, it combines with all the almost all elements.It takes part in reaction by
i) Loss of the only electron to give H+
ii)The gain of an electron to form H-.
iii)Sharing electron to form a single covalent bond.
