Question

why are decomposition reactions called the opposite of combination reactions? write equations for these reactions. ​

Answer 1

Answer:

In a combination reaction two or more substances are combined to form new substance while in the decomposition reaction one substance decomposes into two or more substances. Hence, the decomposition reactions are called opposite of combination reactions.

Answer 2

A decomposition reaction is breakdown or separation of a chemical compound into its elements or simpler compounds while in composition reactions two or more elements or compounds combine to form a single compound that is why decomposition reactions called the opposite of combination reactions.

Decomposition Reaction

CaCO
3
​
→CaO+CO
2
​


NH
4
​
OH→NH
3
​
+H
2
​
O

Combination Reaction

N
2
​
+3H
2
​
→2NH
3
​


CaO+H
2
​
OCa(OH)
2
​

Hope it helps