CHEM 106: 3/17/25

Acid-Base Reactions

• Base on the reactant side and conjugate acid on the product side.

• Acid on reactant side and conjugate base on the product side.

• Important to note that anything on the product side is conjugate to anything on the reactant side.

Conjugates

• Both the reactants and products receive a conjugate label based on their roles in the reaction:

  • Acid: donates a proton (H+).

  • Base: accepts a proton (H+).

Reaction Strength

• Weak Acid: results in a weaker conjugate base.

• Strong Base: results in a weaker conjugate acid.

• Follows the principle that strong acids have negligible conjugate bases (Reference Figure 18.5).

Favorable Reaction Direction

• Acid-base reactions typically favor the side with weaker acids and bases.

• This means that the reaction will move toward forming the more stable (weaker) species.

Hydronium vs. Hydroxide

• Hydronium (H₃O⁺) is very reactive and plays a significant role in acid-base reactions.

Titration Calculations

• Titration calculations are similar to those seen in Chapter 17 but can be simpler due to the consistent structure.

• Starting with a concentration of 0.1 M (point one molar).

• Approximation method used for calculations in specific cases:

  • Generally applied when the change is less than 5%.

Acidic Solutions

• Extent of concentrations: when the concentration of hydrogen ions is greater than the concentration of hydroxide ions, the solution is acidic.

• pH Calculation: Example pH of 5.105 indicates an acidic solution (pH < 7).