Question

$A,B$ and $C$ are three elements which undergo chemical changes as shown below:
(i) $A_2{O}_3+2B\to B_2{O}_3+2A$
(ii) $3CS{O}_4+2B\to B_2(S{O}_4{)}_3+3C$
(iii) $3CO+2A\to A_2{O}_3+3C$
Name the most reactive and the least reactive element.

Answer 1

(i) $A_2{O}_3+2B\to B_2{O}_3+2A$
$B$ replaced $A$
$\therefore B$ is more reactive that $A$.
(ii) $3CS{O}_4+2B\to B_2(S{O}_4{)}_3+3C$
$B$ replaced $C$.
$B$ is more reactive than $C$.
(iii) $3CO+2A\to A_2{O}_3+3C$
$A$ replaced $C$.
$\therefore A$ is more reactive than $C$.
$\therefore$ Order of reactivity.
Most $\leftarrow B>A>C\to C$