Question

explain why the formation of NO is favoured at high temperature​

Answer 1

Answer:

If the temperature drops to room temperature after NO is formed, it is thermodynamically favorable for NO to decompose to nitrogen and oxygen. However, that NO is unstable at room temperature tells us nothing about the rate of the decomposition reaction.

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Answer 2

Answer:

The formation of NO is endothermic (ΔH +ve) so no amount of heating N2 and O2 will cause formation of NO. It is thermodynamically non allowed.

"[NO] decomposes to its elements at elevated temperatures (1100-1200°C), a fact which militates its direct synthesis from N2 and O2."

N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 1st ed. p 512.

NO is thermodynamically unstable but kinetically stable because it requires a high activation energy for decomposition.

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