In a thermite reaction, a compound of iron reacts with a metal.
(a) The metal used is:
(i) Zinc
(ii) Aluminium
(iii) Magnesium
(iv) None of these.
Answer
Aluminium metal is used in thermite reaction .
So, the correct answer is (II).
(b) After completion of this reaction, a metal is obtained in the molten state. Identify the metal:
(i) Zinc
(ii) Aluminium
(iii) Iron
(iv) Magnesium
Answer
Molten iron is obtained at the end of the reaction.
So, the correct option is (iii) Iron
(c) The correct equation to justify thermite reaction is:
(i) Fe 2 O 3 + 2Al → 2Fe + Al 2 O 3 – Heat.
(ii) Fe 2 O 3 + 2Al → 2Fe + Al 2 O 3 + Heat.
(iii) Al 2 O 3 + 2Fe → 2Al + Fe 2 O 3 + Heat.
(iv) Fe 2 O 3 + 2Al → 2Fe + Al 2 O 3
Answer
(ii) Fe 2 O 3 + 2Al → 2Fe + Al 2 O 3+ Heat
(d) The correct name for Fe 2 O 3 is:
(i) Ferrous oxide
(ii) Ferric oxide
(iii) Ferrous hydroxide
(iv) Ferric hydroxide
Answer
- Ferrous is used from Fe 2+
- Ferric is used for Fe 3+
- Here, Fe is oxidised to Fe 3+
Thus, Ferric oxide is the correct name for Fe 2 O 3
So, the correct answer is (II)
