Question

What is the difference between
displacement and double displacement
reaction? Give suitable chemical equations
for the same. (3 marks)​

Answer 1

Answer:

The reaction in which an atom or a set of atoms are displaced by another atom in a molecule is called displacement reaction. For instance, when Iron is added to a copper sulfate solution, it displaces the copper metal.

A + B – C → A – C + B

The above equation exists when A is more reactive than B.

The reaction in which two atoms or a group of atoms are displaced by another atom in a molecule is called a double displacement reaction.

A-B + C-D → A-C + B-D

A and B have to be either:

Halogens where C indicates a cation.

Different metals wherein C indicates an anion.

The difference between displacement reaction double displacement reaction is tabulated below:

Single Displacement reaction Double displacement reaction

In a displacement reaction, a more reactive element replaces a less reactive element from a compound. In a double displacement reaction, two atoms or a group of atoms switch places to form new compounds.

In a displacement reaction, one displacement takes place.

A + BX → AX + B

In a double displacement reaction, two displacements take place to complete the reaction.

AB + CD → AC + BD

Change in color takes place with no precipitate forms. Precipitate is formed.

Metals react with the salt solution of another metal. Salt solutions of two different metals react with each other.

Examples:

2KI + Cl2 → 2KCl + I2 is a displacement reaction.

CuSO4 + Zn → ZnSO4 + Cu is also a displacement reaction.