Question

The reaction of nitrogen with oxygen, to form nitric oxide is an ___________reaction.

Answer 1

Hint: Try to recall that at normal temperatures the nitrogen and oxygen gases do not react with each other but when the temperature is very high, then nitrogen and oxygen reacts to form nitric oxide. Now by using this you can easily answer the given question.

Complete step by step solution:
It is known to you that the reaction between nitrogen and oxygen is quite difficult because at normal temperature the reaction is extremely slow as nitrogen has a triple bond and it is very difficult to break them.
The energy required to break the triple bond of nitrogen is around 941 KJ/mol and due to this a very high temperature is required, so that nitrogen can combine with oxygen to form nitric oxide.
Since, a very high temperature is required to form nitric oxide from nitrogen and oxygen
Hence, the reaction of nitrogen with oxygen to form nitric oxide is an endothermic reaction.

Note: It should be remembered to you that the exhausts of supersonic jet aeroplanes contain nitric oxide which combines with ozone present in the stratosphere to form nitrogen dioxide and diatomic oxygen and this leads to the depletion of the ozone layer. The reaction is:
$NO(g) + {O_3}(g) \to N{O_2}(g) + {O_2}(g)$.
Also, you should remember that nitric oxide is a colourless gas and is paramagnetic due to the presence of unpaired electrons and commercially it is produced by the oxidation of ammonia in the presence of platinum as catalyst in the Ostwald process.