Question

Assertion: Graphite is chemically more reactive than diamond.

Reason: Diamond is very hard but graphite is soft.

• A. if the assertion as well as reason are correct and the reason is correct explanation of assertion.
• B. if the assertion as well as reason are correct, but reason is not the correct explanation of assertion.
• C. If the assertion is correct but reason is not
• D. If the reason is correct but assertion is wrong

Answer 1

The correct option is B

if the assertion as well as reason are correct, but reason is not the correct explanation of assertion.

Graphite and diamond are the allotropes of carbon ($\mathrm{C}$). Both are made up of carbon only, but the linkage is different, the properties are different.

Graphite is soft in nature but diamond is hard.

Graphite has a low melting point but diamond has very high melting point.

Graphite is chemically more reactive than diamond. This statement is true because, in diamond, carbon atom is sp³ hybridised with no free electron but in graphite, carbon atom is sp² hybridised with one free electron. Due to free electrons in graphite, it is more reactive.

Diamond is very hard but graphite is soft. This statement is true because, in graphite, carbon atoms are loosely bound with each other but in diamond, carbon atoms are tightly bound with each other.

Hence, the assertion as well as reason are correct, but reason is not the correct explanation of assertion.

Option B is correct answer.