Question

how does the presence of more than one ionizable proton in a polyprotic acid affect its titration curve compared to a monoprotic acid?
it results in multiple equivalence points.
it creates a single, broad equivalence point.
it decreases the overall ph change per volume of base added.
it increases the time required to reach the equivalence point.
a polyprotic acid has two ionizable protons and the difference between their ka values is more than 1000. how many equivalence points will be present on the titration curve of this acid?

2000

2
1
40
during titration of a diprotic acid, how many moles of naoh are needed to completely neutralize one mole of the diprotic acid?
2
1
4
it depends on the strength of the diprotic acid

Explanation:

• Question 5: Polyprotic acids have multiple ionizable protons. Each proton contributes to a separate ionization step. When titrated with a base, each ionization step has its own equivalence point. For example, \(H_2SO_4\) (a diprotic acid) has two equivalence points in its titration curve.
• Question 6: A polyprotic acid with two ionizable protons (\(n = 2\)) will have \(n\) equivalence points in its titration curve. The condition that the difference between \(K_a\) values is more than 1000 ensures that the two ionization steps are distinct enough to show two separate equivalence points.
• Question 7: A diprotic acid (\(H_2A\)) has the general neutralization reaction \(H_2A+2NaOH = Na_2A + 2H_2O\). From the stoichiometry of the reaction, 1 mole of \(H_2A\) reacts with 2 moles of \(NaOH\) to reach complete neutralization.

Answer:

Question 5: It results in multiple equivalence points.
Question 6: 2
Question 7: 2