Question

Formation of nitric oxide from nitrogen and oxygen is a ________ reaction.
A. Combination
B. Combustion
C. Calcinations
D. Roasting

Answer 1

Nitric oxide consist of one nitrogen and one oxygen molecule. There are various types of reactions like, combination, decomposition, displacement, and double- displacement reactions. Calcination and roasting are methods of extraction of ores by heating the ores.

Complete answer:
Reactions can be of various types in chemistry. Some of the examples are combination reactions, decomposition reactions, displacement reactions and double- displacement reactions, neutralization reactions, etc.
Among them, whenever two reactants react to carry out a reaction and form a single product, then it is called a combination reaction. We have given that nitric oxide is formed from the reaction between nitrogen and oxygen. The reaction is as follows:
${{N}_{2}}+{{O}_{2}}\to 2NO$
As in this reaction we can see that two reactants nitrogen, and oxygen molecule, react to form a single product which is nitrogen oxide, so this reaction is a type of a combination reaction.
Hence, the formation of nitric oxide from nitrogen and oxygen is a combination reaction.

So the correct answer is Option A.

Additional information:
The reaction in which 2 reactants combine is the combination reaction, while when a single substance decomposes in the presence of heat, then more that one product is forms which is called the decomposition reaction, and is the opposite of combination reaction, for example, $2{{H}_{2}}O\to 2{{H}_{2}}+{{O}_{2}}$.

Note:
Combustion is a reaction where any substance reacts with oxygen to form products. Like, $C{{H}_{4}}+2{{O}_{2}}\to C{{O}_{2}}+2{{H}_{2}}O$ combustion of hydrocarbons give carbon dioxide and water. While calcinations and roasting is the process where ores are heated to purify them from volatile substances.