A titration setup was used to determine the unknown molar concentration of a solution of NaOH. A .025 M HCl solution was used as the titration standard. The following data were collected.
Trial 1
Trial 2
Trial 3
Initial NaOH Buret Reading
0.0 mL
12.2 mL
23.2 mL
Final NaOH Buret Reading
12.2 mL
23.2 mL
34.0 mL
Volume of NaOH
What molarity is the NaOH used to neutralize 10.0 mL of the standard HCl solution for the average HCl volume? Sig figs!
Answer
M
What is the pH of the HCl solution?
Answer
What is the pH for the NaOH solution?
Answer
gj
To find the molarity of the NaOH solution used to neutralize 10.0 mL of the standard HCl solution, we need to calculate the average volume of HCl used.
Step 1: Calculate the volume of HCl used in each trial.
Trial 1: Final NaOH Buret Reading - Initial NaOH Buret Reading = 12.2 mL - 0.0 mL = 12.2 mL
Trial 2: Final NaOH Buret Reading - Initial NaOH Buret Reading = 23.2 mL - 12.2 mL = 11.0 mL
Trial 3: Final NaOH Buret Reading - Initial NaOH Buret Reading = 34.0 mL - 23.2 mL = 10.8 mL
Step 2: Calculate the average volume of HCl used.
Average Volume = (Volume Trial 1 + Volume Trial 2 + Volume Trial 3) / 3
Average Volume = (12.2 mL + 11.0 mL + 10.8 mL) / 3 = 11.3 mL
Step 3: Calculate the Molarity (M) of the NaOH using the average volume of HCl used.
Molarity of NaOH = Molarity of HCl * Volume of HCl / Volume of NaOH
Molarity of NaOH = 0.025 M * 11.3 mL / 10.0 mL
Now, we can solve for the molarity of NaOH using the values we have.
Molarity of NaOH = (0.025 M * 11.3 mL) / 10.0 mL = 0.02825 M (rounded to the appropriate number of significant figures) = 0.028 M
The molarity of the NaOH used to neutralize 10.0 mL of the standard HCl solution is 0.028 M (rounded to the appropriate number of significant figures).
To calculate the pH of the HCl solution, we need to know the concentration of the HCl solution. Based on the information provided, we only have the volume of the HCl solution (0.025 M). Therefore, we cannot directly calculate the pH of the HCl solution. In order to calculate the pH, we need the concentration of the HCl solution.
Similarly, we cannot calculate the pH of the NaOH solution without knowing its concentration. The pH of the solution is determined by its concentration of H+ or OH- ions, which in turn depends on the concentration of the NaOH solution.
To determine the molar concentration of the NaOH solution, we can use the equation:
M1V1 = M2V2
Where M1 is the molar concentration of the HCl solution, V1 is the volume of the HCl solution used, M2 is the molar concentration of the NaOH solution, and V2 is the volume of the NaOH solution used.
From the data given, we know that the molar concentration of the HCl solution (M1) is 0.025 M and the volume of the HCl solution used (V1) is 10.0 mL.
To find the average HCl volume (V2), we can calculate the mean of the final NaOH buret readings from the three trials:
Average HCl Volume (V2) = (Final NaOH Buret Reading - Initial NaOH Buret Reading) / 3
From the data given, the initial NaOH buret readings for the three trials are 0.0 mL, 12.2 mL, and 23.2 mL respectively. And the final NaOH buret readings are 12.2 mL, 23.2 mL, and 34.0 mL respectively.
Substituting the values into the equation:
Average HCl Volume (V2) = [(12.2 - 0) + (23.2 - 12.2) + (34.0 - 23.2)] / 3
= (12.2 + 11.0 + 10.8) / 3
= 34.0 / 3
= 11.33 mL
Now that we have all the values, we can solve for the molar concentration of the NaOH solution (M2):
M2 = (M1V1) / V2
= (0.025 M * 10.0 mL) / 11.33 mL
= 0.022072 M
Rounding to the correct number of significant figures, the molar concentration of the NaOH solution is 0.022 M.
Next, to find the pH of the HCl solution, we need to understand that HCl is a strong acid. Strong acids completely dissociate in water, so the concentration of H+ ions in the HCl solution is equal to the concentration of the HCl solution itself.
Therefore, the pH of the HCl solution can be calculated using the formula:
pH = -log[H+]
Substituting the molar concentration of the HCl solution into the formula, we get:
pH = -log(0.025)
= -(-1.60)
= 1.60
So the pH of the HCl solution is 1.60.
Finally, the pH of the NaOH solution can be determined by using the formula:
pOH = -log[OH-]
Now, since NaOH is a strong base, it completely dissociates in water, so the concentration of OH- ions in the NaOH solution is equal to the concentration of the NaOH solution itself. Therefore, the pOH of the NaOH solution is equal to the pH.
pOH = pH = 1.60
So the pH of the NaOH solution is 1.60.
mLacid x Macid = mLbase x Mbase. Substitute and solve for the unknown.
pH = -log(H^+) but do you want pH of the initial HCl or the pH after neutralization.