# Worksheet: The Henderson–Hasselbalch Equation

In this worksheet, we will practice using the Henderson–Hasselbalch equation, calculating pH from the pKa and concentrations of conjugate acid–base pairs.

Q1:

Consider the equilibrium shown.

What is in a solution of 0.125 M and 0.130 M at ?

• A M
• B M
• C M
• D M
• E M

Q2:

Consider the equilibrium shown.

What is in a solution of 0.065 M and 0.040 M?

• A
• B
• C
• D
• E

Q3:

What concentration of is required to make in a 0.200 M solution of ? of is .

Q4:

Consider the equilibrium shown.

What is in a solution of 1.35 M and 0.82 M?

• A M
• B M
• C M
• D M
• E M

Q5:

What concentration of is required to make in a 0.320 M solution of ? of hydrofluoric acid is .

Q6:

A 1.00 L aqueous buffer solution is prepared from 0.20 mol and 0.40 mol. The of is and the self-ionization constant of water, , is . Calculate, to 1 decimal place, the pH of the buffer solution.

Q7:

To 2 significant figures, what mass of must be added to 0.650 L of a 0.120 M solution of to give a buffer solution with a pH of 9.08? Assume a negligible change in volume when the solid is added. The of is .

Q8:

A buffer solution is prepared from equal volumes of 0.200 M acetic acid and 0.600 M sodium acetate. The of acetic acid is .

Is the solution acidic, neutral, or basic?

• AAcidic
• BNeutral
• CBasic

Q9:

Saccharin, , is a weak acid (). If a 0.250 L solution with a buffered pH of 5.48 is prepared from g of sodium saccharide, , what is the equilibrium concentration of saccharin in the solution?

• A M
• B M
• C M
• D M
• E M

Q10:

A 0.500 L aqueous buffer solution is prepared from and . The of is and the self-ionization constant of water, , is . Assuming that behaves as a monoprotic acid, calculate, to 1 decimal place, the pH of the buffer solution.

Q11:

Consider the shown equilibrium.

What is in a solution of 0.25 M and 0.030 M?

• A M
• B M
• C M
• D M
• E M