Let's go through the details step-by-step to determine the major species present at equilibrium when 0.1 mol of KOH is added to 1.0 L of a solution that is 0.4 M in both NH₃ and NH₄Br.
Step 1: Dissociation of KOH in Water
- KOH is a strong base and dissociates completely in water:
[tex]\[ \text{KOH} \rightarrow \text{K}^+ + \text{OH}^- \][/tex]
Step 2: Dissociation of NH₄Br in Water
- NH₄Br, being a salt, also dissociates completely in water:
[tex]\[ \text{NH}_4\text{Br} \rightarrow \text{NH}_4^+ + \text{Br}^- \][/tex]
Step 3: Equilibrium Consideration of NH₃ in Water
- NH₃ is a weak base and will partially dissociate in water to form NH₄⁺ and OH⁻:
[tex]\[ \text{NH}_3 + \text{H}_2\text{O} \rightleftharpoons \text{NH}_4^+ + \text{OH}^- \][/tex]
Step 4: Identification of Major Species Acting as Acids and Bases
- To identify the acids, we look for species that can donate a proton (H⁺ ion).
- To identify the bases, we look for species that can accept a proton (H⁺ ion).
Based on the dissociations and equilibrium provided:
- The NH₄⁺ ion will act as an acid because it can donate a proton.
- NH₃ can accept a proton and thus acts as a base.
- OH⁻ is a base because it can accept a proton to form water.
Step 5: Identification of Species that are Neither Acids nor Bases
- K⁺ and Br⁻ ions do not participate in proton transfer and are neither acids nor bases.
Final Answer: Listing the Species in the Appropriate Categories
- Acids: [tex]\(\text{NH}_4^+\)[/tex]
- Bases: [tex]\(\text{NH}_3, \text{OH}^-\)[/tex]
- Other: [tex]\(\text{K}^+, \text{Br}^-\)[/tex]
So, the final answer is:
Acids:
[tex]\[ \text{NH}_4^+ \][/tex]
Bases:
[tex]\[ \text{NH}_3, \text{OH}^- \][/tex]
Other:
[tex]\[ \text{K}^+, \text{Br}^- \][/tex]
