Given #1*mol*L^-1# concentrations of #"hydrochloric, acetic, and formic acids"# in water, can you rank the solutions in order of INCREASING #pH#?

1 Answer
Oct 2, 2016

Answer:

#pH=-log_10[H_3O^+]#; #pH# follows the order #HCl# #<# #HCO_2H# #<# #H_3C-CO_2H# with respect to #1# #mol*L^-1# concentrations of these acids.

Explanation:

And thus the STRONGEST acid will generate the LOWEST, i.e. the most negative #pH#. The given order is wrong.

#HCl# completely dissociates to give #pH=-1#. Formic acid should be a stronger acid than acetic acid, and will thus have a more negative #pH#; you will look up the #pK_a# values to verify what I say.