Question

Which of the following gives the correct increasing order of acidic strength?

• A. Water < Acetic acid < Hydrochloric acid
• B. Water < Hydrochloric acid< Acetic acid
• C. Acetic acid< Water < Hydrochloric acid
• D. Hydrochloric acid< Water< Acetic acid

Answer 1

The correct option is A

Water < Acetic acid < Hydrochloric acid

Explanation for correct option:

A. Water < Acetic acid < Hydrochloric acid

Acidic strength:

• Acid strength is the measure of the ability of the acid to lose its ${\mathrm{H}}^{+}$ ion.
• An acid is said to be a strong acid if it dissociates completely in an aqueous solution.
• A weak acid is the one in which dissociation takes place partially.
• The order of acidic strength is as follows:

Water < Acetic acid < Hydrochloric acid

• Since Hydrochloric acid$\left(\mathrm{HCl}\right)$ is a strong acid. Thus it has the highest acidic strength or it can dissociate completely, acetic acid$\left({\mathrm{CH}}_3\mathrm{COOH}\right)$ is a weak acid as it dissociates partially into ${\mathrm{H}}^{+}$ions while water$\left({\mathrm{H}}_2\mathrm{O}\right)$ is a neutral solution.

Explanation for incorrect options:

The correct order of acidic strength is Water < Acetic acid < Hydrochloric acid. Thus, options B, C, and D are incorrect.

Hence, the correct option is A i.e. Water < Acetic acid < Hydrochloric acid.