Question

Identify the equation that shows the reaction of ethane with chlorine in the presence of ultraviolet light.

• A. C_2H_6 + Cl_2 C_2H_6Cl_2
• B. C_2H_6 + Cl_2 C_2H_4Cl_2 + H_2
• C. C_2H_6 + Cl_2 C_2H_5Cl + HCl
• D. C_2H_6 + Cl_2 2CH_3Cl

Hint:

Substitution reactions are characteristic of saturated compounds, while addition reactions are characteristic of unsaturated compounds (alkenes/alkynes)!

Answer 1

The Correct Option is C

Step 1: Understanding the Reaction Type: 
Ethane is a saturated hydrocarbon (alkane). Alkanes undergo substitution reactions with halogens where hydrogen atoms are replaced one by one. 

Step 2: The Role of UV Light: 
UV light provides the energy required to break the Cl-Cl bond to start the free-radical chain reaction. 

Step 3: Writing the Products: 
One hydrogen atom from ethane (C_2H_6) is replaced by one chlorine atom to form chloroethane (C_2H_5Cl). The displaced hydrogen atom bonds with the second chlorine atom to form hydrogen chloride (HCl). 

Step 4: Final Answer: 
The balanced equation is C_2H_6 + Cl_2 C_2H_5Cl + HCl.