Q.

Assertion: General formula of alkanes is CnH2n+2
Reason: It is because they are saturated compounds.

1 Both assertion and reason are correct and reason is the correct explanation of assertion.  
2 Both assertion and reason are correct, but reason is not the correct explanation of assertion.  
3 Assertion is true, but reason is false.  
4 Assertion is false, but reason is true.  

Ans.

(2)

Alkanes are saturated compounds because they are very stable. Thus, both assertion and reason are correct but reason is not the correct explanation of the assertion.