Return to Blog
Homepage
MCAT Chemistry – Acids
- by
- Feb 05, 2015
- MCAT Blog, MCAT Chemistry, MCAT Question of the Day
In the titration of acid HA against the strong base NaOH, which of the following acids will form a neutral solution at the equivalence point?
I. HCl
II. HF
III. HI
A) I only
B) I and II only
C) I and III only
D) I, II, and III
Explanation
This question is testing your understanding of acid-base titrations and the contents of the solution formed at the equivalence point. To answer this question, you must know that at the equivalence point the solution consists of 100% of the conjugate base and water. Therefore, at the equivalence point of HCl, HF, and HI, the solution will contain water and Cl–, F–, and I–, respectively. The conjugate base of a strong acid does not react with water. Therefore, I and III will form a neutral solution. The conjugate base of a weak acid does however react with water to produce the weak acid and hydroxide, as follows:
A– + H2O —> HA + OH–
Hydrofluoric acid is a weak acid despite being a hydrogen halide and therefore will form a basic solution at the equivalence point. Thus, C is the correct answer.
Want more MCAT practice?
We’ve got options for every schedule and learning style!
From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT Advisor using the form below. No obligation, just expert advice.
Related Posts
Search the Blog
Free Consultation
Interested in our Online MCAT Course, One-on-One MCAT Tutoring or Med admissions packages? Set up a free consultation with one of our experienced Senior Student Advisors.
Schedule NowPopular Posts
-
-
MCAT Blog What's on the MCAT? -
-
-
MCAT Blog How to Review MCAT Full Lengths
Free MCAT Practice Account
Need great MCAT practice?Get the most representative MCAT practice possible when you sign up for our free MCAT Account, which includes a half-length diagnostic exam and one of our full-length MCAT practice exams.
Learn More