Question

give reasons

1. air holes of a gas burner have to be adjusted when the vessels being heated get blackened by the flame.

2. use of synthetic detergents cause water pollution.

Answer 1

1 because the heat from the burner does not reach the vessel.
2 because the contain synthethic things which cause pollution.
hope it helps.

Answer 2

Hi friend
Here's the answer
(1). Air holes of gas burners are to be adjusted because when they are blocked they give unsaturated hydrocarbons which results in sooty flame which blackens the utensils.
(2). Use of synthetic detergent cause water pollution because they are non-biodegradable which harms the environment.
Hope that my answer helps you