Question

Which is the stronger base Cl or Br $?$

Answer 1

Hint :First we know that an acid is a substance that accepts a pair of valence electrons or donates protons to form a bond. To compare the strength of bases using the strengths of their conjugate acids, we need to know that stronger acids form weaker conjugate bases, and weaker acids form stronger conjugate bases. Hence, we need to find which acid is weaker than the other.

Complete Step By Step Answer:
Bases are electron donors because it is a substance that can accept protons or donate a pair of valence electrons to form a bond.
Since we know that the order of acidity is $I>Br>Cl>F$ .
Clearly $Br$ is more acidic nature than $Cl$
Hence, $Cl$ is a stronger base than $Br$ .

Additional Information:
Sodium hydroxide is the strongest base as it is completely dissociated to give sodium ions and hydroxide ions. Weak bases are the basic substances that do not completely ionize in water. An example of a weak base is ammonia.

Note :
The strength of the base is arranged on the basis of its ability to donate electron pairs.
The more stable lone pair will be the weaker base. For example, a lone pair on a neutral atom will be more stable and less basic than a lone pair on a negatively charged atom.