Question

which reaction displays an example of an arrhenius base?
○ naoh(s) → na⁺(aq) + oh⁻(aq)
○ hcl(g) + h₂o(l) → h₃o⁺(aq) + cl⁻(aq)
○ ch₃cooh(aq) + h₂o(l) → h₃o⁺(aq) + ch₃coo⁻(aq)
○ nh₃(aq) + hc₂h₃o₂(aq) → nh₄⁺(aq) + c₂h₃o₂⁻(aq)

Explanation:

1. Recall the definition of an Arrhenius base: A substance that dissociates in water to produce hydroxide ions ($\ce{OH^{-}}$).
2. Analyze each option:

• Option 1: $\ce{NaOH(s)}$ dissociates into $\ce{Na^{+}}$ and $\ce{OH^{-}}$ ions. This fits the Arrhenius base definition as it produces $\ce{OH^{-}}$ in solution.
• Option 2: $\ce{HCl}$ is an Arrhenius acid (produces $\ce{H3O^{+}}$) when reacting with water, not a base.
• Option 3: $\ce{CH3COOH}$ (acetic acid) is a weak acid that donates a proton to water, producing $\ce{H3O^{+}}$, so it's an acid, not a base.
• Option 4: This is a reaction between a base ($\ce{NH3}$) and an acid ($\ce{HC2H3O2}$) in a Bronsted - Lowry acid - base reaction (proton transfer), not an Arrhenius base reaction as $\ce{NH3}$ does not dissociate to produce $\ce{OH^{-}}$ directly in the way defined by Arrhenius.

Answer:

A. $\ce{NaOH(s)
ightarrow Na^{+}(aq) + OH^{-}(aq)}$