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. Process – A is a chemical change.
• B. Process – B is a chemical change.​
• C. Both processes A and B are chemical changes.​
• D. None of these processes is a chemical change.​

Answer 1

The correct option is C Both processes A and B are chemical changes.​

Correct answer: (iii) The process A and process B both are chemical changes.​

​​​​​​● The process A involves the change of animal waste to a new substance biogas. So, process A is chemical change.​

● The process B involves the burning of biogas as fuel which produces new substances like carbon dioxide and heat. So, process B is also a chemical change.​

$\text{Biogas}⟶\text{Carbon dioxide}\left(CO2\right)+\text{Heat}$