. Buffered solutions are mixtures of a weak acid and its conjugate ate base. Explain why a mixture of a strong acid and its conjugate base (such as HCl and Cl^-) is not buffered.

Interpretation:

The reason for a mixture of a strong acid and its conjugate base is not buffered should be explained.

Concept Introduction:

A buffer solution can be defined as an aqueous solution which is capable of resisting pH changes upon addition of small amounts of a strong base and a strong acid as well as upon dilution by distilled water(or in general water).The action that corresponds to keep the resistance to any changes on pH is known as “ buffering”. A buffer solution has a distinct definite pH value and hence is valuable in reaction conditions where one needs to maintain the pH value at a constant value. Blood is an example of a natural buffer which usually maintains the pH value around 7.4.

There can be two main kinds of buffer systems depending on the pH values that one needs to achieve in preparation of the buffer solutions. The two main kinds are acidic and basic buffer solutions. In both these kinds of buffer solutions there are two main constituents.

In an acidic buffer a weak acid and its conjugate base are the two main components in the buffer system.

Whereas in a basic buffer solution a weak base and its conjugate acid are the two main components in the buffer system.

In order for a solution to successfully function as a buffer solution it must contain a conjugate acid base pair which involves a weak acid/base.

According to Lowry-Bronsted acid base theory an acid is defined as a substance that is capable of donating protons (H+ ions) whereas a base is a substance that is capable of abstracting protons (H+ ions).

In a general acid equilibrium shown by equation (2), an acid would donate a proton to water to form a conjugate base of the form A-.Then the conjugate base A- will have the ability to function as a base by abstracting an H+ from hydronium io0n to become HA (acid form).The extent to which this backward reaction occur depends on the strength of the acid...