If the pH at one-half the equivalence point of a weak acid is 5.25, which of the following acids is being titrated?

Propionic acid: Ka = 1.3 × 10^-5
Carbonic acid: Ka = 4.2 × 10^-7
Pyridinium: Ka = 5.6 × 10^-6
Hypochlorous acid: Ka = 2.0 × 10^-11

A. Hypochlorous acid
B. Carbonic acid
C. Propionic acid
D. Pyridinium

Question

If the pH at one-half the equivalence point of a weak acid is 5.25, which of the following acids is being titrated? 

Propionic acid:	Ka = 1.3 × 10^-5	
Carbonic acid:	Ka = 4.2 × 10^-7	
Pyridinium:	Ka = 5.6 × 10^-6	
Hypochlorous acid: Ka = 2.0 × 10^-11

 		A.	Hypochlorous acid
 		B.	Carbonic acid
 		C.	Propionic acid
 		D.	Pyridinium

misssunshinexxoxo · Answer

@vera_ewing Which do you believe it is?

misssunshinexxoxo · Answer

Hypochlorous acid is a weak acid with the chemical formula HClO. It forms when chlorine dissolves in water, and it is HClO that actually does the disinfection when chlorine is used to disinfect water for human use

misssunshinexxoxo · Answer

Seems like that one to me

rushwr · Answer

pH= -log10 (H+)
From that you can fine the H+ Concentration. I got 5.624 * 10^-6 . So that means it is pyridinium right?