Question

Bacteria digest animal waste and produce biogas (step – I). The Biogas is then burnt as fuel (step – II). Choose the correct statement from the following.
a. Only step – I is a chemical change.
b. Only step – II is a chemical change.
c. Both steps – I & II are chemical changes.
d. Both steps – I & II are physical changes.

Answer 1

Dear Student,

◆ Answer -

(c) Both steps – I & II are chemical changes.

● Explanation -

• In both steps (production of biogas and its burning), chemical composition of participating substances change.
• Hence, both are chemical changes.

◆ Extra information -

• In chemical change, composition of substance changes.
• It involves rearrangement of atoms.
• For example, baking of cake, ripening of fruits, rancidity of butter.

Thanks dear. Hope this helps you...

Answer 2

Explanation:

both 1 and 2 and chemical changes