Question

Alnico is an alloy used to make permanent magnets.
(a) Which is the metal present in Alnico in addition to iron, nickel and cobalt?
(b) Compounds in the process of extraction of aluminium are given:
$A{l}_2{O}_3\to Al(OH{)}_3\to N{a}_{3}Al{O}_3\to A{l}_2{O}_3.2H_{2}O$
If there is any mistake in the order of the compounds, write them in the correct order.
(c) "To extract $Al$ from its ore, carbon is not used as a reducing agent". Justify the statement.

Answer 1

(a) Aluminium
(b) $A{l}_2{O}_3.2H_{2}O\to N{a}_{3}Al{O}_3\to Al(OH{)}_3\to A{l}_2{O}_3$
(c) Oxides of highly reactive metals like aluminium have great affinity towards oxygen and so, cannot be reduced by carbon.