Practice Quiz

Praxis II General Science

Category - Chemistry

Start a Study Session Sign up for Question of the Day
Diprotic acids, such as H2SO4, are able to donate two protons to a solution. However, the dissociation constant for the second proton is usually much lower than for the first. This is because:
  1. After the first proton reaches equilibrium, no more protons can dissociate.
  2. Diprotic acids are able to give two protons.
  3. The second proton is a weak acid, so it dissociates faster.
  4. The 2nd proton’s dissociation is affected by the presence of protons already in solution.
  5. None of the above are correct.
Explanation
Answer: D - The 2nd proton dissociates slowly because of two factors: the presence of hydrogen ions already in solution from the 1st proton, and the fact that the 2nd ionization of the conjugate base requires more energy. After the first dissociation, the conjugate base is negatively charged (-1). To remove a second proton, thus making the charge -2, requires more energy.
Was this helpful? Upvote!
Login to contribute your own answer or details
Start a Study Session Sign up for Question of the Day

Top questions

Related questions

Most popular on PracticeQuiz