⚗️ Determining Whether an Cation is Acidic or pH-Neutral

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Q. Classify each cation as a weak acid or pH-neutral (neither acidic nor basic).

(a) C5H5NH+
(b) Ca2+
(c) Cr 3+
(d) Li+
(e) CH3NH3+
(f) Fe3+

(a) The C5H5NH+ cation is the conjugate acid of a weak base. This ion is therefore, a weak acid.
(b) The Ca2+ cation is the counterion of a strong base. This ion is therefore, pH-neutral (neither acidic nor basic).
(c) The Cr3+ cation is a small, highly charged metal cation. It is therefore, a weak acid.

[kianaahmadzadi]

Thank you so much I completely understood this content

[Taffoman]

What would you say is something that works as a rule in determining Ions properties? Like Lithium, it's a group 1 element. Do elements in group 1 usually take in OH ion due their ionic charge? And Why does HF dissociate, I would have thought that was a match made in heaven. I feel like chemistry teaching is too concerned about people knowing Bronsted-Lowry that they forget to tell Why a substance donates a proton or forms H3O+ cation.