Question

Traces of molybdenum are used with finely divided iron which acts as a catalyst during Haber's process for the synthesis of ammonia. Here molybdenum:

• A. acts as a promoter to increase the activity of the catalyst
• B. acts as a poison to decrease the activity of the catalyst
• C. provides a new pathway to the reaction
• D. forms another intermediate compound with lesser activation energy

Answer 1

The correct option is A acts as a promoter to increase the activity of the catalyst

• Substances, which accelerate the rate of a chemical reaction and themselves remain chemically and quantitatively unchanged after the reaction, are known as catalysts.
  
• Promoters are substances that enhance the activity of a catalyst while poisons decrease the activity of a catalyst.
• In Haber’s process for manufacture of ammonia, molybdenum acts as a promoter for iron which is used as a catalyst.

$N_2\left(g\right)+3H_2\left(g\right)\to 2N{H}_3\left(g\right)$