calculate the ph of resulting solution when 2.50 ml of the 2.60 M acetic acid is diluted to make a 250.0 ml solution
See your post above.
To calculate the pH of the resulting solution, we need to determine the concentration of acetic acid after dilution. The dilution formula is:
C1V1 = C2V2
Where:
C1 = initial concentration of acetic acid (2.60 M)
V1 = initial volume of acetic acid (2.50 mL)
C2 = final concentration of acetic acid (unknown)
V2 = final volume of the resulting solution (250.0 mL)
Rearranging the formula to solve for C2:
C2 = (C1 x V1) / V2
C2 = (2.60 M x 2.50 mL) / 250.0 mL
C2 = 0.026 M
Now that we have determined the final concentration of the acetic acid, we can use the Henderson-Hasselbalch equation to calculate the pH of the resulting solution, which is given by:
pH = pKa + log([A-] / [HA])
The pKa of acetic acid is 4.76, and the ratio of the concentration of the acetate ion ([A-]) to the concentration of acetic acid ([HA]) can be calculated using the final concentration of acetic acid:
[A-] / [HA] = 10^(-pH-pKa)
0.026 / [HA] = 10^(-pH-4.76)
Now, let's solve for [HA]:
[HA] = 0.026 / 10^(-pH-4.76)
We know that [HA] + [A-] = 0.026 M, so we can substitute this into the equation:
0.026 / 10^(-pH-4.76) + [A-] = 0.026
Simplifying the equation:
1 / 10^(-pH-4.76) + [A-] = 1
Rearranging the equation:
1 / 10^(-pH-4.76) = 1 - [A-]
Simplifying further:
10^(-pH-4.76) = 1 / (1 - [A-])
Taking the logarithm of both sides:
-pH - 4.76 = log(1 / (1 - [A-]))
Rearranging the equation to solve for pH:
pH = -log(1 / (1 - [A-])) - 4.76
Substituting the value of [A-]:
pH = -log(1 / (1 - 0.026)) - 4.76
pH = -log(1 / 0.974) - 4.76
pH = -log(1.026) - 4.76
pH = -0.0109 - 4.76
pH = -4.77
Therefore, the pH of the resulting solution when 2.50 mL of 2.60 M acetic acid is diluted to make a 250.0 mL solution is approximately -4.77.
To calculate the pH of the resulting solution, we need to determine the concentration of acetic acid in the diluted solution. Here's how you can do it:
1. Start by calculating the moles of acetic acid in the initial solution.
- Moles = Molarity x Volume
- Moles = 2.60 M x 0.00250 L
- Moles = 0.0065 mol
2. Next, determine the volume of the resulting solution. Since you diluted 2.50 ml of the initial solution to make a 250.0 ml solution, the total volume is 250.0 ml.
3. Now, calculate the concentration of acetic acid in the resulting solution.
- Concentration = Moles / Volume
- Concentration = 0.0065 mol / 0.250 L
- Concentration = 0.026 M
4. To find the pH of the resulting solution, we'll use the equation for calculating the pH of a weak acid solution, which is:
- pH = -log[H+]
5. Acetic acid partially ionizes in water, so we can assume that the concentration of hydrogen ions ([H+]) is equal to the concentration of acetic acid.
6. Substitute the concentration of acetic acid (0.026 M) into the pH equation:
- pH = -log(0.026)
- pH ≈ 1.59
Therefore, the pH of the resulting solution, when 2.50 ml of the 2.60 M acetic acid is diluted to make a 250.0 ml solution, is approximately 1.59.