Question

choose the option below that is an acid ionization reaction.
select the correct answer below:
○ h₂o + hf ⇌ f⁻ + h₃o⁺
○ h₂o + nh₂⁻ ⇌ oh⁻ + nh₃
○ cn⁻ + h₂o ⇌ oh⁻ + hcn
○ h₂o + h₂po₄⁻ ⇌ h₃po₄ + oh⁻

Explanation:

Step1: Recall acid ionization reaction definition

An acid ionization reaction is when an acid donates a proton (\(H^{+}\)) to a base. In the Brønsted - Lowry theory, an acid is a proton donor.

Step2: Analyze each option

• For \(H_{2}O + HF

ightleftharpoons F^{-}+H_{3}O^{+}\):

• \(HF\) donates a proton (\(H^{+}\)) to \(H_{2}O\). \(HF\) acts as an acid (proton donor), and \(H_{2}O\) acts as a base (proton acceptor). This is an acid ionization reaction of \(HF\).
• For \(H_{2}O + NH_{2}^{-}

ightleftharpoons OH^{-}+NH_{3}\):

• \(H_{2}O\) donates a proton (\(H^{+}\)) to \(NH_{2}^{-}\). Here \(H_{2}O\) is the acid (proton donor), but the question is about acid ionization. If we consider the general form of acid ionization (\(HA + H_{2}O

ightleftharpoons A^{-}+H_{3}O^{+}\)), \(NH_{2}^{-}\) is not a typical acid in the context of this problem's requirement (we are looking for an acid like \(HF\) which is a common acid for ionization).

• For \(CN^{-}+H_{2}O

ightleftharpoons OH^{-}+HCN\):

• \(H_{2}O\) donates a proton (\(H^{+}\)) to \(CN^{-}\). \(H_{2}O\) is the acid (proton donor), but \(CN^{-}\) is a base (\(CN^{-}+H^{+}\to HCN\)). This is a base - ionization (hydrolysis) type of reaction (where a base reacts with water to produce hydroxide ions) rather than the ionization of a typical acid like \(HF\).
• For \(H_{2}O + H_{2}PO_{4}^{-}

ightleftharpoons H_{3}PO_{4}+OH^{-}\):

• \(H_{2}O\) donates a proton (\(H^{+}\)) to \(H_{2}PO_{4}^{-}\). \(H_{2}O\) is the acid (proton donor), but \(H_{2}PO_{4}^{-}\) is acting as a base (\(H_{2}PO_{4}^{-}+H^{+}\to H_{3}PO_{4}\)) in this reaction. This is not the ionization of a common acid like \(HF\) which is what we expect for an acid - ionization reaction.

Answer:

\(H_{2}O + HF
ightleftharpoons F^{-}+H_{3}O^{+}\)