P-1 Chemical reactions and equations — Science STD 10 — Question

In redox reaction, the reductant is oxidized by the oxidant and the oxidant is reduced by the
reductant.
Example:CuO $( s )+ H _{2( g )} \rightarrow Cu _{( s )}+ H _2 O$
In this reaction, oxygen is removed from copper oxide therefore it is a reduction of $CuO$, while hydrogen accepts oxygen to form water that means oxidation of hydrogen takes place. Thus oxidation and reduction reactions occur simultaneously.
Other examples of redox reactions:
$
2 H _2 S + SO _2 \rightarrow 3 S +2 H _2 O
$
$MnO _2+4 HCl \rightarrow MnCl _2+2 H _2 O + Cl _2 \uparrow$