Question

Anaerobic bacteria digest animal waste and produce biogas (change A). The biogas is then burnt as fuel (change B) . The following statements pertain to these changes. Choose the correct one:
(a) A is a chemical change where as B is physical change
(b) B is a chemical change where as A is physical change
(c) Both A and B are physical change

Answer 1

Answer:

a is a chemical change where b is a physical change

Explanation:

due....to....when the animal take their meal after this digestion happen in the digestive system and for that digestion is a chemical change..!!

and the biogas as we all know that we made biogas much...!!

Answer 2

Answer:

Change A and change B both are chemical changes.

As both the reaction are irreversible, they lead to the formation of new substances.

Explanation:

Animal waste (anaerobic bacteria)⇒ Bio gas

Bio gas (burning)⇒ $CO_{2}$ + other substance