Which of the following are combination reactions?
(i) 2KClO3 2KCl + 3O2
(ii) MgO + H2O → Mg(OH)2
(iii) 4Al + 3O2→ 2Al2O3
(iv) Zn + FeSO4→ ZnSO4 + Fe
In reaction (ii), MgO + H2O → Mg(OH)2
MgO and water combined together to form a single product, i.e., magnesium hydroxide.
In reaction (iii), 4Al + 3O2→ 2Al2O3
Aluminium combines with oxygen to form a single product. i.e., aluminum oxide
Hence, both are examples of combination reactions.