Question

Which of the following is an example of a double replacement reaction?

(a)3Fe + 2O2 Fe3O4
(b) BaCl2 + K2CO3 BaCO3 + 2KCl
(c) NiCO3 NiO + CO2
(d) Cl2 + 2NaBr 2NaCl + Br2

Answer 1

b) is an example of a Double Displacement Reaction:

Ba Cl2 + K2 CO3 ---> Ba CO3 + 2K Cl
A B C D A D B C

Answer 2

Answer: The correct answer is Option b.

Step-by-step explanation:

Double displacement reactions are defined as the reactions in which exchange of ions takes place.

`AB+CD\rightarrow CB+AD`

For the given options:

Option a:
`3Fe+2O_2\rightarrow Fe_3O_4`

This is an example of synthesis reaction.

Option b:
`BaCl_2+K_2CO_3\rightarrow BaCO_3+2KCl`

This is an example of double displacement reaction.

Option c:
`NiCO_3\rightarrow NiO+CO_2`

This is an example of decomposition reaction.

Option d:
`Cl_2+2NaBr\rightarrow 2NaCl+Br_2`

This is an example of single displacement reaction.

From the above information, the correct answer is Option b.