Question

$AlC{l}_3+K\to Al+3KCl$
If the number of electrons lost or gained during the changes is $x$. Then, the value of $x$ is :

Answer 1

Given a reaction:
$AlC{l}_3+K\to Al+3KCl$
If the number of electrons lost or gained during the changes is $x$. Then, the value of $x$ is $3$.
The balanced chemical equation is $AlC{l}_3+3K\to Al+3KCl$
The oxidation number of potassium changes from $0$ to $+1$.
Thus, the change in the oxidation number per atom of K is $1$.
Total change in the oxidation number for $3$ K atoms is $3$.
Hence, $3$ electrons are involved in the redox reaction.
Thus, $x=3$.