# Acidic strength order of mineral acids in acetic acid

Explain this acidic strength order $$\ce{H2SO4} > \ce{HCl} > \ce{HNO3}$$ in acetic acid.

### My Attempt

Stability of conjugate base is proportional to the acidic strength of acids in acetic acid.

1. $$\ce{SO4^2-}$$ has two resonance structures.
2. $$\ce{NO3-}$$ has three resonance structures.
3. $$\ce{Cl-}$$ is stable due to octet formation.

As for electronegativity order, Cl is on par with N (almost equal).

According to stability, $$\ce{HNO3}$$ must me more acidic than $$\ce{HCl}.$$ Also, electronegativity of N & Cl is almost the same.

So, according to me, the order must be $$\ce{HNO3} > \ce{H2SO4} > \ce{HCl}.$$

Where am I wrong? Please explain.

• The anions are so different that "comparing" them for a trend is meaningless. – MaxW Sep 21 '19 at 16:28
• The strength of the acid is not only dependent on the stability of the conjugate base but also on the proton-accepting ability of the solvent (For protic acids). HCl for example, is a strong acid in water and weak acid in pure acetic acid for this reason. – Shoubhik R Maiti Sep 21 '19 at 20:51
• @MaxW but such questions are asked in exams.if there is no way to compare them then how should i approach such question in exams. – Math Geek Sep 22 '19 at 7:07
• @ShoubhikRajMaiti i want to know more about "Effects of different solution on acid strength ". Can you please add me in a separate chat so that i can ask little bit more. please. – Math Geek Sep 22 '19 at 7:16
• Note that you should consider rather $\ce{HSO4- }$ instead of $\ce{SO4^2-}$ – Poutnik Sep 23 '19 at 4:31