Question 12: 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.
(i) Process − A is a chemical change.
(ii) Process − B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.
Question 12: 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.
(i) Process − A is a chemical change.
(ii) Process − B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.