Gen. Chem. II Lecture 25: Common Ion & Buffers

Flashcards covering key concepts from the chemistry lecture on common ions and buffers, including definitions, calculations, and applications.

What is the Common Ion Effect?

The Common Ion Effect refers to the impact on the pH of a weak acid or base ionization caused by the addition of a salt containing the same ion formed during ionization.

How does the addition of a common ion affect equilibrium?

The addition of a product ion pushes the ionization equilibrium towards the reactants, causing a decrease in [H3O+] and an increase in pH.

What is the Ka value for formic acid (HCOOH)?

Ka for formic acid is 1.8 x 10^-4.

What are buffers?

Buffers are solutions that resist changes in pH when an acid or base is added.

What is the typical pH range of blood?

The pH of blood is typically between 7.35 and 7.45.

What determines the pH of a buffer?

The pH of a buffer can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log([Con Base]/[Acid]).

What is Buffer Capacity?

Buffer capacity is the amount of acid or base a buffer can consume before experiencing significant pH change.

What are the components in a buffer solution?

A buffer solution typically contains a weak acid and its conjugate base or a weak base and its conjugate acid.

How do you calculate the pH when mixing two solutions to create a buffer?

You determine concentrations after dilution and then apply the Henderson-Hasselbalch equation.

Which acid/base mixture would be best for a buffer with pH=3.50?

Formic acid with formate (Ka= 1.8x10^-4) is a suitable choice for a buffer with pH=3.50.