Which of the following will behave as a strong acid when added to water?
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 H2SO4 has maximum ability to donate H+ in the aqueous solution. Also, H2SO4 can donate two H+ ions per molecule while all other acids can donate only one H+ ion in the solution. Hence, H2SO4 is the strongest acid among the given acids.