Chemistry
Explain the following:
(a) Zinc is used to cover iron so as to prevent rusting of iron. Why?
(b) In construction work, why is the alloy of aluminium–duralumin used rather than pure aluminium?
Answer
(a) As zinc is more reactive than iron, hence it forms a dense and impermeable layer of zinc oxide over iron which protects the iron beneath from rusting.
(b) As duralumin has strength up to six times greater than pure aluminium hence, alloy of aluminium–duralumin is used rather than pure aluminium in construction work.
Related Questions
Given below in column A is a schematic diagram of the electrolytic reduction of alumina. Identify the parts labelled as A, B and C with the correct options from the Column B.
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(b) In Hoope's process, pure aluminium is collected at the …………… (top/bottom) of the electrolytic cell.
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