25 mL 0.1 M acetic acid is titrated with 0.1 M NaOH. Calculate the pH after the addition of 0.0 mL, 1.0 ml, 2.5 mL, 4.0 mL, 7.0 mL, 10.5 mL, 15.0 mL, 17.0 mL, 20.0 mL, 22.0 mL, 23.0 mL, 23.5 mL, 24.0 mL, 24.25 mL, 24.5 mL, 24.75 mL, 25.0 mL, 25.25 mL, 25.5 mL, 25.75 mL, 26.0 mL, 26.5 mL, 27.0 mL, 28.0 mL, 30.0 mL, and 33.0 mL NaOH.
Be serious. Tell us what you don't understand about this and perhaps we can get you started. 26 problems. Sheesh!
No
To calculate the pH at different volumes of NaOH added, we need to consider the reaction between acetic acid and NaOH. Acetic acid is a weak acid and reacts with NaOH, which is a strong base, in a neutralization reaction:
CH3COOH + NaOH -> CH3COONa + H2O
In this reaction, acetic acid (CH3COOH) reacts with NaOH to form sodium acetate (CH3COONa) and water (H2O).
At the start of the titration (0.0 mL NaOH added), we have only acetic acid in the solution. The acetic acid is a weak acid, so we need to calculate its pH. To do this, we need to find the concentration of acetic acid after dilution due to the addition of NaOH.
Given:
Volume of acetic acid (V1) = 25 mL
Concentration of acetic acid (C1) = 0.1 M
Initial volume of NaOH added (V2) = 0.0 mL
Concentration of NaOH (C2) = 0.1 M
To find the concentration of acetic acid after dilution, we can use the equation:
C1V1 = C2V2
0.1 M * 25 mL = C2 * 0.0 mL
The initial concentration of acetic acid remains the same because no NaOH has been added yet. Therefore, the concentration of acetic acid after dilution is still 0.1 M.
Now, to determine the pH at different volumes of NaOH added, we can use the Henderson-Hasselbalch equation, which relates the pH of a weak acid solution to its pKa and the ratio of the concentrations of the conjugate base and acid forms.
The pKa of acetic acid is 4.74, and the conjugate base is acetate (CH3COO-).
The Henderson-Hasselbalch equation is:
pH = pKa + log([CH3COO-] / [CH3COOH])
At the start of the titration (0.0 mL NaOH added), the ratio [CH3COO-] / [CH3COOH] is zero since no NaOH has reacted yet. Therefore, the pH is calculated by:
pH = 4.74 + log(0 / 0.1)
Since log(0) is undefined, we can conclude that at 0.0 mL NaOH added, the pH of the solution remains at the acidic level of the acetic acid, which is approximately 2.4.
Now, by following this approach, you can calculate the pH at each given volume of NaOH added.