Question

Name the five common acids. Justify the reason for these acids being termed as “common”.

Answer 1

Hint: There are various definitions for an acid where each definition gives an appropriate property of what an acid is. These acids can be organic and inorganic in nature and they contain various elements such as sulphur, chlorine and nitrogen as their constituents apart from carbon and hydrogen. They have several uses as some organic acids are found in sour fruits and food additives such as vinegar.

Complete Step by Step Solution:
An acid can be defined according to three different definitions.

A. Arrhenius Theory: According to this theory, any compound which can donate a proton (\[{H^ + }\]) in an aqueous solution is an acid. For example:
\[HN{O_3}(Acid) \Leftrightarrow {H^ + } + NO_3^ - \]

B. Bronsted Lowry Theory: It is the extended version of Arrhenius theory. According to this, any substance which and donate a proton or H+ ion to form a conjugate base can be considered as an acid. To generate an acid, the conjugate base can accept a proton. For example,
\[HF \Leftrightarrow {H^ + } + {F^ - }\] (Conjugate base)
\[{F^ - } + {H^ + } \Leftrightarrow HF\] (acid)

C. Lewis Theory: It is one of the most widely used theories. According to this theory, any substance which can accept a pair of electrons can be considered to be acids. For example:
Among all these different theories of acid-base, the five common acids are: Sulphuric acid (\[{H_2}S{O_4}\]), Nitric acid (\[HN{O_3}\]) Hydrochloric acid (HCl), Acetic acid (\[C{H_3}COOH\]) and Citric acid (COOH-CH₂-C(OH)COOH-CH₂-COOH) are organic acids and while the later is found in vinegar while the former is found in citrus fruits.

Note: Acids are highly corrosive in nature. They can burn your skin and cause deep wounds. We should always handle acids with care and take precautions while using them in the lab.