Question

Which of the following will behave as a strong acid when added to water?

• A. ${\text{C}}_2{\text{H}}_5\text{COOH}$
• B. ${\text{H}}_2{\text{SO}}_4$
• C. $\text{HCOOH}$
• D. ${\text{CH}}_3\text{COOH}$

Answer 1

The correct option is B ${\text{H}}_2{\text{SO}}_4$

Strength of acid depends on the ability of the compound to donate the proton and the number of protons it can donate in the solution. Among all the given acids ${\text{H}}_2{\text{SO}}_4$ has maximum ability to donate $H^{+}$ in the aqueous solution. Also, ${\text{H}}_2{\text{SO}}_4$ can donate two $H^{+}$ ions per molecule while all other acids can donate only one $H^{+}$ ion in the solution. Hence, ${\text{H}}_2{\text{SO}}_4$ is the strongest acid among the given acids.