Question

how can u show that during a chemical reaction :
a)gas is evolved ?
b)change in smell takes place?​

Answer 1

Answer:

gas is evolved during a chemical reaction

Answer 2

a)  A gas evolution reaction is a chemical process that produces a gas, such as oxygen or carbon dioxide.

Acids react with carbonates to produce salt, carbon dioxide, and water.

Limewater can be used to detect the presence of carbon dioxide evolved in a reaction.

Hydrogen can be detected by its burning 'POP' sound.

b) When two or more compounds or elements are mixed and a scent or odor is present, a chemical reaction has taken place.

For example, when an egg begins to smell, (a rotten egg) a chemical reaction has taken place. This is the result of chemical decomposition.

It can be easily detected by smelling it.