Question

What type of chemical reaction takes place when
1.Limestone is heated?
2.Proteins are converted into amino acids?
A) In both 1) and 2) combination reactions is taking place
B) In 1) Decomposition reaction takes place and in 2) combination reaction takes place
C) In both 1) and 2) Decomposition reactions are taking place
D) In 1) Combination reaction takes place and in 2) Decomposition reaction takes place

Answer 1

Hint: There are many types of reactions such as combination, displacement, double displacement or decomposition reaction. Combination reaction is the one in which reactants are combined together to form a new product. Addition of hydrogen and oxygen gas to produce water is an example of a combination reaction.

Complete answer:
Let’s look at the reaction first then we can easily identify the type of reaction:
When limestone is heated, the reaction is a type of thermal decomposition which can be represented below: Calcium carbonate is a chemical name for limestone which is heated to form calcium oxide and carbon dioxide. We can write the chemical equation for this reaction as,
\[CaC{O_3}\left( s \right) \rightleftharpoons CaO\left( s \right) + C{O_2}\left( s \right)\]
So we can conclude that this reaction is a type of double decomposition reaction.
Now, the next is conversion of proteins into amino acids so in this the fundamental reaction of protein synthesis is the formation of a peptide bond between the carboxyl group at the end of a growing polypeptide chain and a free amino group on an incoming amino acid.
This reaction is also a decomposition reaction.
So we can conclude that the correct option for this question is option C i.e. both the reactions are decomposition reactions.

Note:
We have to know that the decomposition reaction can be defined as the reaction in which a single compound splits into two or more simple substances under suitable conditions. It is just the opposite of the combination reaction. It occurs when one reactant breaks down into two or more products.