Sulfuric acid is a diprotic acid, strong in the first ionization step and weak in the second (Ka2=1.1X10^-2). Using appropriate calculations, determine whether it is feasible to titrate 10.00mL of 0.1 M H2SO4 to two distinct equivalence points with 0.1 M NaOH.
To determine if it is feasible to titrate 10.00 mL of 0.1 M H2SO4 to two distinct equivalence points with 0.1 M NaOH, we need to consider the stoichiometry of the reaction and the acid dissociation constants.
Given that sulfuric acid (H2SO4) is a diprotic acid (meaning it can donate two protons), we need to consider the ionization of both protons separately.
The chemical equation for the reaction between H2SO4 and NaOH is:
H2SO4 + 2NaOH → Na2SO4 + 2H2O
For the first equivalence point, we are interested in the reaction between the first proton (H1) of H2SO4 and NaOH. The balanced equation for this reaction is:
H1 + NaOH → Na+ + H2O
Since H2SO4 is a strong acid, it completely dissociates in water. Thus, we can assume that 10.00 mL of 0.1 M H2SO4 contains 0.001 moles of H2SO4, which is also equivalent to 0.002 moles of H1.
In the reaction, 1 mole of H1 reacts with 1 mole of NaOH. Since the concentration of NaOH is 0.1 M, 0.002 moles of H1 can react with 0.002 moles of NaOH. This means that 0.002 moles of NaOH are required to reach the first equivalence point.
Now, let's consider the second equivalence point, which involves the reaction between the second proton (H2) of H2SO4 and NaOH. The balanced equation for this reaction is:
H2 + NaOH → Na+ + H2O
Since the concentration of H2SO4 is 0.1 M, it means the concentration of H2 is also 0.1 M. Therefore, 10.00 mL of 0.1 M H2SO4 contains 0.001 moles of H2SO4, which is equivalent to 0.001 moles of H2.
Similarly, in the reaction, 1 mole of H2 reacts with 1 mole of NaOH. Since the concentration of NaOH is 0.1 M, 0.001 moles of H2 can react with 0.001 moles of NaOH. This means that 0.001 moles of NaOH are required to reach the second equivalence point.
Comparing the amounts of NaOH required for the first and second equivalence points, we can see that 0.002 moles of NaOH are needed for the first equivalence point, whereas only 0.001 moles of NaOH are needed for the second equivalence point.
Since we have a fixed volume of H2SO4 (10.00 mL), we cannot reach two distinct equivalence points using 0.1 M NaOH. The amount of H2SO4 is limited, and the excess NaOH from the first equivalence point would react with the remaining H2SO4, preventing the occurrence of a separate second equivalence point.
In conclusion, it is not feasible to titrate 10.00 mL of 0.1 M H2SO4 to two distinct equivalence points with 0.1 M NaOH.