The correct order of increasing acidic nature is?

  1. #"H"_3"O"^+ < "NH"_4^+ < "HF" < "OH"^(-) < "H"_2"O"#

  2. #"NH"_4^+ < "HF" < "H"_3"O"^+ < "H"_2"O" < "OH"^-#

  3. #"OH"^(-) < "H"_2"O" < "NH"_4^+ < "HF" < "H"_3"O"^+#

  4. #"H"_3"O"^+ < "HF" < "H"_2"O" < "NH"_4^+ < "OH"^-#

1 Answer
Oliver S.
Apr 8, 2018

3.

Explanation:

Acidic nature is determined by a low #pH#.
#pH# is given by:
#pH=-log [H_3O^+]#
where #[H_3O^+]# is the concentration of oxonium ions- so the most acidic species in this bunch must be the oxonium ion-#H_3O^+#

Conversely, an alkaline character is given by a high #pH#, which implies a high concentration of #OH^-# ions- so this must be what has the last acidic character of the listed ions and molecules.

Hence the only appropriate one seems to be option 3.

Related questions
Impact of this question
1539 views around the world
You can reuse this answer
Creative Commons License