Question

State whether the following statements are true or false. In case a statement is false, write the corrected statement in your notebook.​

(a) Cutting a log of wood into pieces is a chemical change.
(b) Formation of manure from leaves is a physical change
(c) Iron pipes coated with zinc do not get rusted easily.
(d) Iron and rust are the same substances.
(e) Condensation of steam is not a chemical change.

Answer 1

(a) False​. Correct answer -
Cutting of a log of wood into pieces does not change the composition of wood, so it is a physical change which is irreversible.

(b)False. Correct answer -

Formation of manure from leaves is a chemical change because it leads to formation of new substance manure.

(c) True. Correct answer - ​
Applying a thin coating of zinc on iron articles prevents rusting because zinc hinders the direct contact of air with iron.

(d) False. Correct answer - ​
Rust is the chemical substance which is formed after the reaction of iron with water in the presence of air. So, iron and rust are not the same substances.

(e) True. Correct answer -

Condensation is the process by which steam is converted into liquid form. So, only the state of water changes from gas to liquid. So, condensation is not a chemical change.