Question

A hydrocarbon X undergoes the reaction under suitable conditions as shown below. 

 

• A. X only
• B. Y only
• C. X and Z
• D. Y and Z

Hint:

A quick way to spot an unsaturated hydrocarbon is its formula: Alkenes follow (C_nH_2n), while Alkanes follow (C_nH_2n+2).

Answer 1

The Correct Option is B

Step 1: Understanding the Reaction (Cracking): 
The reaction described is thermal cracking, where a long-chain saturated hydrocarbon (alkane) is broken down into a smaller alkane and an unsaturated hydrocarbon (alkene). 

Step 2: Identifying the Compounds: 
X (Butane): (C_4H_10). This is an alkane. All carbon-carbon bonds are single bonds (Saturated). Y (Propene): (C_3H_6). This is an alkene. It contains at least one carbon-carbon double bond (Unsaturated). Z (Methane): (CH_4). This is the simplest alkane (Saturated). 

Step 3: Defining Unsaturated: 
Unsaturated hydrocarbons are those that contain double or triple covalent bonds between carbon atoms. In this reaction, only propene (Y) fits this definition. 
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Step 4: Final Answer: 
Compound Y only is unsaturated.