Sabatier–Senderens reaction involves _____________ in the presence of Ni?

The Sabatier–Senderens reaction is an important hydrogenation process in organic chemistry, discovered by Paul Sabatier and Jean-Baptiste Senderens in the early 1900s. This reaction involves the addition of hydrogen (H₂) to unsaturated hydrocarbons, such as alkenes or alkynes, in the presence of a nickel (Ni) catalyst. The main purpose of this reaction is to convert unsaturated compounds into saturated hydrocarbons — typically alkanes.

The general reaction can be written as:
RCH=CHR + H₂ → RCH₂–CH₂R
Here, an alkene reacts with hydrogen gas in the presence of nickel to form an alkane.

Catalyst Used:
Nickel (Ni) is the most common catalyst for this reaction, but other metals like palladium (Pd) and platinum (Pt) can also be used. Nickel is widely preferred because it is inexpensive and provides high catalytic efficiency at moderate temperatures (around 200°C).

Mechanism (Simplified):

1. 
   

   Hydrogen molecules adsorb onto the surface of the nickel catalyst.

   
   


2. 
   

   The alkene also adsorbs onto the catalyst surface.

   
   


3. 
   

   Hydrogen atoms add to the carbon atoms of the double bond.

   
   


4. 
   

   The saturated hydrocarbon (alkane) is released from the catalyst surface.

   
   

This reaction is an example of a catalytic hydrogenation process — one of the most important industrial reactions used to produce saturated compounds from unsaturated feedstocks.

Applications:

• 
  

  Used in the hydrogenation of vegetable oils to produce margarine and other solid fats.

  
  


• 
  

  Plays a crucial role in petroleum refining and organic synthesis.

  
  


• 
  

  Demonstrates the principle of heterogeneous catalysis in organic chemistry.

  
  

Key Facts:

• 
  

  Reactants: Alkene and H₂

  
  


• 
  

  Catalyst: Nickel (Ni)

  
  


• 
  

  Product: Alkane

  
  


• 
  

  Temperature: Approximately 200°C

  
  


• 
  

  Type: Hydrogenation reaction

  
  


• 
  

  Discovered by: Paul Sabatier and Jean-Baptiste Senderens

  
  

✅ Correct Answer: A) Alkene & H₂