To determine which reaction yields a salt with the highest pH, we need to consider the nature of the acids and bases involved in each reaction. When a strong base reacts with a weak acid, the resulting salt tends to be basic, leading to a higher pH. Let's analyze each reaction in detail:
1. Reaction: [tex]\( KOH + H_2 SO_4 \)[/tex]
- Potassium hydroxide (KOH) is a strong base.
- Sulfuric acid ([tex]\( H_2 SO_4 \)[/tex]) is a strong acid.
- The reaction of a strong base with a strong acid produces a neutral salt and water:
[tex]\( KOH + H_2 SO_4 \rightarrow K_2 SO_4 + H_2O \)[/tex]
- Since both the base and acid are strong, the salt produced (potassium sulfate) will be neutral.
2. Reaction: [tex]\( Cu(OH)_2 + H_2 SO_4 \)[/tex]
- Copper(II) hydroxide ([tex]\( Cu(OH)_2 \)[/tex]) is a weak base.
- Sulfuric acid ([tex]\( H_2 SO_4 \)[/tex]) is a strong acid.
- The reaction of a weak base with a strong acid produces an acidic salt and water:
[tex]\( Cu(OH)_2 + H_2 SO_4 \rightarrow CuSO_4 + 2H_2O \)[/tex]
- The resulting salt (copper(II) sulfate) will be acidic due to the strong acidic influence.
3. Reaction: [tex]\( NH_4 OH + HCl \)[/tex]
- Ammonium hydroxide ([tex]\( NH_4 OH \)[/tex]) is a weak base.
- Hydrochloric acid (HCl) is a strong acid.
- The reaction of a weak base with a strong acid produces an acidic salt and water:
[tex]\( NH_4 OH + HCl \rightarrow NH_4 Cl + H_2O \)[/tex]
- The resulting salt (ammonium chloride) will be acidic due to the strong acid.
4. Reaction: [tex]\( NaOH + CH_3 COOH \)[/tex]
- Sodium hydroxide (NaOH) is a strong base.
- Acetic acid ([tex]\( CH_3 COOH \)[/tex]) is a weak acid.
- The reaction of a strong base with a weak acid produces a basic salt and water:
[tex]\( NaOH + CH_3 COOH \rightarrow NaCH_3 COO + H_2O \)[/tex]
- The resulting salt (sodium acetate) will be basic due to the strong base.
From these analyses, we can conclude that the reaction yielding a salt with the highest pH is:
[tex]\[
\boxed{NaOH + CH_3 COOH}
\][/tex]
