f 20.0mL of 0.122M NaOH are required to reach the first equivalent point of a solution of citric acid(tripotic acid H3C6H5O7).How many mL of NaOH in total are required to reach the second equivalence point?
To determine the total volume of NaOH required to reach the second equivalence point, we need to know the number of equivalents of citric acid present in the solution.
Citric acid (H3C6H5O7) is a triprotic acid, meaning it can donate three protons (H+ ions) per molecule. Therefore, it requires three equivalents of NaOH to neutralize one mole of citric acid.
Since the first equivalence point is reached with 20.0 mL of 0.122 M NaOH, we can calculate the number of moles of NaOH used:
(0.122 M)(0.0200 L) = 0.00244 moles of NaOH
Since each mole of citric acid requires three equivalents of NaOH, the number of moles of citric acid neutralized at the first equivalence point is also 0.00244 moles.
To reach the second equivalence point, we know that three equivalents of NaOH are required to neutralize one mole of citric acid. Therefore, to find the total volume of NaOH needed to reach the second equivalence point, we need to determine the number of moles of citric acid in the solution.
Assuming we have x moles of citric acid in the solution, we can set up the following equation based on the reaction between citric acid and NaOH:
3x = 0.00244 moles
Solving for x, we get:
x = 0.00244 moles ÷ 3 = 0.000813 moles of citric acid
Now, to find the total volume of NaOH required to reach the second equivalence point, we use the molarity and number of moles of citric acid:
Total volume of NaOH (L) = (Number of moles of citric acid) ÷ (Molarity of NaOH)
Total volume of NaOH (L) = 0.000813 moles ÷ 0.122 M = 0.006665 L
Finally, we convert the volume from liters to milliliters:
Total volume of NaOH (mL) = 0.006665 L × 1000 mL/L ≈ 6.67 mL
Therefore, approximately 6.67 mL of NaOH are required to reach the second equivalence point.
To determine the volume of NaOH required to reach the second equivalence point in the citric acid solution, we need to understand the stoichiometry of the reaction.
Citric acid (H3C6H5O7) is a triprotic acid, meaning it can donate three protons (H+) per molecule.
The balanced chemical equation for the reaction between citric acid and NaOH is:
H3C6H5O7 + 3 NaOH → 3 H2O + Na3C6H5O7
From the equation, we can see that each mole of citric acid reacts with 3 moles of NaOH.
Given that we used 20.0 mL of 0.122M NaOH to reach the first equivalence point, we can calculate the number of moles of NaOH used.
Step 1: Calculate the moles of NaOH used in reaching the first equivalence point:
Moles of NaOH = Volume (L) × Concentration (mol/L)
Moles of NaOH = 0.0200 L × 0.122 mol/L
Moles of NaOH = 0.00244 mol
Since three moles of NaOH are required to reach one mole of citric acid, we can calculate the number of moles of citric acid used at the first equivalence point:
Moles of citric acid = (0.00244 mol NaOH) / 3
Moles of citric acid = 0.000813 mol
Now, to determine the volume of NaOH required to reach the second equivalence point, we need to find the number of moles of citric acid remaining after the first equivalence point:
Step 2: Calculate the moles of citric acid remaining after the first equivalence point:
Moles of citric acid remaining = (Initial moles of citric acid) - (Moles of citric acid used)
Moles of citric acid remaining = 0.000813 mol - 0.000813 mol
Moles of citric acid remaining = 0 mol
At the second equivalence point, all the remaining moles of citric acid would be neutralized. Since the initial moles of citric acid remaining is 0, we know that the second equivalence point is reached when all the citric acid is neutralized.
Therefore, we can conclude that no additional volume of NaOH is required to reach the second equivalence point because all the citric acid has already been neutralized.
In summary, no additional mL of NaOH is required to reach the second equivalence point since all the citric acid has already been neutralized at the first equivalence point.