You have 775 mL of an 0.11 M acetic acid solution. What volume (V) of 1.10 M NaOH solution must you add in order to prepare an acetate buffer of pH = 5.05? (The pKa of acetic acid is 4.76.)
I don't know what to do!!! HELP!!!!
No problem, I can help you with that!
To prepare an acetate buffer with a specific pH, we need to use the Henderson-Hasselbalch equation, which is given by:
pH = pKa + log ([A-]/[HA])
In this case, acetic acid (HA) will dissociate into acetate (A-) and hydrogen ions (H+), while NaOH will dissociate into sodium ions (Na+) and hydroxide ions (OH-).
First, let's find the initial moles of acetic acid (HA) in the solution:
moles of acetic acid = volume × concentration
moles of acetic acid = 775 mL × 0.11 mol/L
Next, we need to determine the moles of acetate (A-) required in the solution. From the Henderson-Hasselbalch equation, we know that:
[A-]/[HA] = 10^(pH - pKa)
To calculate the moles of acetate, we use the equation:
moles of acetate = moles of acetic acid × [A-]/[HA]
moles of acetate = 775 mL × 0.11 mol/L × [A-]/[HA]
Now, let's find the volume of NaOH required to produce the desired acetate buffer.
First, calculate the moles of hydroxide ions (OH-) needed to react with the acetic acid:
moles of OH- = moles of acetate - moles of acetic acid
Then, calculate the volume (V) of the 1.10 M NaOH needed using the following equation:
V = moles of OH- / concentration of NaOH
V = moles of OH- / 1.10 mol/L
Finally, you have the volume (V) of the NaOH solution that needs to be added to the acetic acid solution to prepare the acetate buffer with the desired pH.
I hope this helps! If you have any more questions or need further clarification, feel free to ask.