- A
, displacement reaction - B
, combination reaction - C
, combination reaction
Solution:
Concept- Concept- When an atom or group of atoms in a molecule are replaced by another atom, this is referred to as a displacement reaction. For instance, copper metal is displaced when iron is added to a solution of copper sulphate. Iron nails chemically react with
solution.The reaction between iron and copper sulphate is as follows;
Iron displaces copper from its solution and forms ferrous sulphate and atomic copper. Thus it is an example of a displacement reaction.This reaction is called displacement reaction. Due to the production of 
, the blue colour of the solution, , is lost. Due to the formation of an insoluble copper layer on iron nails, they no longer appear glossy.Hence, the correct answer is option 1.
