Question

Reaction of zinc with dilute nitric acid gives ______ gas.

Answer 1

Hint : The reaction between zinc metal and dilute nitric acid results in the formation of nitric oxide a gas evolved during this reaction, soluble zinc nitrate and water whereas when the concentration of nitric acid changes, products formed are also different.

Complete Step By Step Answer:
This is the basic concept of chemical reaction. Here the reaction is occurring between zinc and dilute nitric acid. First let us get some information about nitric acid.
Nitric acid is highly corrosive metal acid and is colourless. It is a primary reagent used in nitration of organic compounds.it is also a strong oxidising agent thus, it has high industrial value.
Nitric acid undergoes thermal and light decomposition thus, it is stored in a brown glass bottle. On the other hand zinc is a reactive metal.
Reaction of zinc and nitric acid is concentration dependent.it depends on the concentration of nitric acid. In this reaction usually zinc nitrate is prepared.
Now there are two reactions between zinc and nitric acid. It depends whether nitric acid is hot and concentrated or cold and dilute. Both reactions result in the formation of different products.
Let us see the reaction of hot and concentrated nitric acid with zinc metal.
When zinc reacts with concentrated nitric acid it produces nitrogen gas with water. The colour of the nitrogen gas is reddish brown.
The produced nitrogen gas can be used as a rocket fuel and as an oxidising agent.
On the other hand the reaction between zinc metal and dilute nitric acid is completely different.
When zinc and dilute nitric acid reacts it results in the formation of nitric oxide $(NO)$ , along with soluble zinc nitrate and water.
Thus we can conclude that when zinc reacts with dilute nitric acid nitric oxide is evolved.
Therefore the answer is nitric oxide.

Note :
Reaction of zinc with nitric acid depends on the concentration of nitric acid whether it is dilute or concentrated. In both the cases different gas is evolved. When nitric acid is concentrated, nitrogen dioxide is produced whereas in case of dilute nitric acid, nitric oxide is produced as both are different compounds.