question_answer 15)

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 the above processes is a chemical change

Answer:

(c) Both processes A and B are chemical changes. Bacteria acts on waste and converts it to biogas (change A). Hence, it is a chemical change during biogas production (change B), it works as fuel and produces and heat. Hence, A and B both are chemical changes.