Question

Draw the conjugate acid of $$C{l}^{-}$$.

Answer 1

Hint: The concept of conjugate acid and base were given by the Brønsted-Lowry, where the theory establishes a relationship between the acid and bases in terms of protons. The donor of protons are the acids in this case, and after the donation the anion is the conjugate base of the original molecule. Similarly, the acceptor of proton are the bases and after it accepts the proton, it becomes the conjugate acid of the original compound.

Complete step by step answer:
The theory of Brønsted-Lowry defines interactions of acid-base in terms of proton transfer between chemical species. A Brønsted-Lowry acid is any species that has an ability to donate a proton, and similarly a base is any species that has an ability to accept a proton. In terms of chemical representation of the structure, this means that any Brønsted-Lowry acid must contain a hydrogen which can dissociate as $$H^{+}$$ . In order to have the ability to accept a proton, a Brønsted-Lowry base must have at least one lone pair of electrons in order to form a new bond with a proton.
Using the definition of Brønsted-Lowry, we can say that an acid-base reaction is any reaction in which a proton is transferred from an acid and is accepted by a base. We can use the definitions of Brønsted-Lowry to discuss acid-base reactions in any given solvent, and those that occur in the gaseous phase.
In a reaction of Brønsted-Lowry acid-base, a conjugate acid can be defined as the species which are formed after the base accepts a proton. In contrast to conjugate acid, a conjugate base is the species which are formed after an acid donates its proton. Together the two species are called a conjugate acid-base pair, and they have the same molecular formula except for the acid which has an extra $$H^{+}$$ compared as to the conjugate base.
In case of $$C{l}^{-}$$ , the conjugate acid would have an extra proton, so the chemical reaction which represents and justifies the formation of conjugate acid of chloride ion is shown below.
$$HCl+H_{2}O\to C{l}^{-}+H_3{O}^{+}$$
Here we can see that chloride ion is formed when the hydrochloric acid loses a proton. So the conjugate acid would be $HCl$ .

Note: In the reaction which is represented in the complete solution, the $HCl$ donates its proton to the water molecule therefore acting as an acid. And the water molecule accepts the proton and forms hydronium ion, therefore acting as a base.