Determine whether or not the mixing of each pair of solutions results in a buffer. a. 100.0 mL of 0.10 M NH₃; 100.0 mL of 0.15 M NH₄Cl

Verified step by step guidance

1. Identify the components of a buffer solution: a weak base and its conjugate acid, or a weak acid and its conjugate base.
2. Recognize that NH_3 (ammonia) is a weak base and NH_4^+ (from NH_4Cl) is its conjugate acid.
3. Calculate the moles of NH_3: \( \text{moles of NH}_3 = 0.10 \text{ M} \times 0.100 \text{ L} \).
4. Calculate the moles of NH_4^+: \( \text{moles of NH}_4^+ = 0.15 \text{ M} \times 0.100 \text{ L} \).
5. Determine if both components (NH_3 and NH_4^+) are present in significant amounts to form a buffer.

Key Concepts

Buffer Solutions

A buffer solution is a system that resists changes in pH upon the addition of small amounts of acid or base. It typically consists of a weak acid and its conjugate base or a weak base and its conjugate acid. This equilibrium allows the buffer to neutralize added acids or bases, maintaining a relatively stable pH.

Weak Bases and Conjugate Acids

In the context of buffers, a weak base is a substance that partially ionizes in solution, establishing an equilibrium between the base and its conjugate acid. For example, ammonia (NH3) is a weak base, and when mixed with its conjugate acid, ammonium chloride (NH4Cl), it can form a buffer system that helps maintain pH stability.

Henderson-Hasselbalch Equation

The Henderson-Hasselbalch equation is a mathematical formula used to calculate the pH of a buffer solution. It relates the pH to the concentration of the weak acid and its conjugate base, expressed as pH = pKa + log([A-]/[HA]). This equation is essential for determining whether a given mixture can function as a buffer.