Buffer Solutions and pH Concepts

This video tutorial explains buffer solutions, which consist of a weak acid and its conjugate base, and their role in maintaining a constant pH level. It covers the chemical reactions involved when acids or bases are added to a buffer solution and how these reactions prevent significant pH changes. The tutorial also introduces the Henderson-Hasselbalch equation for calculating the pH of buffer solutions and provides practice problems to reinforce understanding.

What components make up a buffer solution?

• A strong acid and a strong base

• A weak acid and a strong base

• A weak acid and its conjugate base

• A strong acid and a weak base

What is the primary function of a buffer solution?

• To maintain a constant pH level

• To neutralize all acids and bases

• To increase the pH of a solution

• To decrease the pH of a solution

How does a buffer solution respond when a strong acid is added?

• The pH remains relatively stable

• The pH decreases significantly

• The solution becomes neutral

• The pH increases significantly

What equation is used to calculate the pH of a buffer solution?

• Henderson-Hasselbalch equation

• Boyle's law

• Avogadro's law

• Arrhenius equation

In the Henderson-Hasselbalch equation, what does the term 'pKa' represent?

• The concentration of the acid

• The acid dissociation constant

• The concentration of the base

• The base dissociation constant

What happens to the pH of a buffer solution when the concentration of the weak acid equals the concentration of the conjugate base?

• The pH is greater than the pKa

• The pH equals the pKa

• The pH is less than the pKa

• The pH is neutral

If the ratio of base to acid in a buffer solution is 10:1, how does the pH compare to the pKa?

• The pH equals the pKa

• The pH is one unit higher than the pKa

• The pH is one unit lower than the pKa

• The pH is neutral

In a buffer solution, if the pH is measured to be 5.62 and the concentration of the base is greater than the acid, what can be inferred about the pKa?

• The pKa equals 5.62

• The pKa is less than 5.62

• The pKa is neutral

• The pKa is greater than 5.62

What is the pH of a buffer solution containing 0.75 M acetic acid and 0.5 M sodium acetate, given the pKa of acetic acid is 4.74?

• 4.00

• 4.74

• 5.00

• 4.57

How do you calculate the pKa of an unknown weak acid if the pH and concentrations of the acid and base are known?

• Subtract the log of the base to acid ratio from the pH

• Add the pH to the log of the acid concentration

• Add the log of the base to acid ratio to the pH

• Subtract the pH from the log of the base concentration