Answer:
The best choice to create a buffer with pH = 2.07 is chlorous acid
Explanation:
To choose the pH of a buffer you must know that the nearest pH to pKa of the buffer, the better buffer capacity (quantitative measure of the resistance to change of pH of a buffer)
If you see, in the problem, the acid that has the pKa nearest to desire pH (2.07), is chlorous acid (HClO₂; pKa = 1.95). Thus, the best choice to create a buffer with pH = 2.07 is chlorous acid.
