Question

Ethene and ethyne differ in the

• A. number of carbons
• B. number of bonds
• C. number of hydrogens
• D. (B) and (C)

Answer 1

The Correct Option is D

Ethene and ethyne are both hydrocarbons containing two carbon atoms.  

Ethene ($C_2H_4$) has a double bond between the two carbon atoms and four hydrogen atoms. Its structure is $CH_2=CH_2$. 
Ethyne ($C_2H_2$) has a triple bond between the two carbon atoms and two hydrogen atoms. Its structure is $CH\equiv CH$. 

Comparing ethene and ethyne: 

Number of carbons: Both have 2 carbon atoms, so they don't differ in the number of carbons. * 
Number of bonds: Ethene has a double bond, while ethyne has a triple bond. Therefore, they differ in the number of bonds. * 
Number of hydrogens: Ethene has 4 hydrogen atoms, while ethyne has 2 hydrogen atoms. 

Therefore, they differ in the number of hydrogens. Since ethene and ethyne differ in the number of bonds and the number of hydrogens, the correct answer is (4).