Which of the following is NOT a decomposition reaction?
a NH4NO2 (s) + N2(g) + H2O(1)
b
H2O2(aq) + H2O(l) + O2(g)
C KCl(s) → K(s) + Cl2(g)
d Al(s) + HCl(aq) + AICI: (aq) + H2(g)

Al + HCl   →   AlCl₃  + H₂

Its single displacement reaction.

Explanation:

Chemical equation:

2NH₄NO₃  →  2N₂ + 4H₂O + O₂

It is the decomposition reaction in which ammonium nitrate decompose to give nitrogen , water and oxygen.

Chemical equation:

2H₂O₂  →  2H₂O + O₂

It is the decomposition reaction in which hydrogen peroxide decompose to give water and oxygen.

Chemical equation:

2KCl    →   2K + Cl₂

It is the decomposition reaction in which potassium chloride decompose to give its constituent elements potassium and chlorine.

Chemical equation:

2Al +6 HCl   →   2AlCl₃  +3 H₂

This is single replacement reaction in which aluminium react with HCl and form aluminium chloride and hydrogen.

the answer is option a.