CHEM 3341A Acid strength questions

CHEM 3341A Acid strength questions - The amino acid is a...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEM 3341A Lecture Questions 1. Which is a stronger acid, H 3 C C OH O or H 3 C C SH O ? The second acid, H 3 C C SH O , is stronger. This is because the sulfur atom is larger than oxygen. The larger size of sulfur makes it better able to accommodate a negative charge (larger volume of space for electrons). Since the conjugate base H 3 C C S O is weaker or more stable, H 3 C C SH O is the stronger acid. 2. Explain why amino acids are stronger acids than “normal” carboxylic acids.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: The amino acid is a stronger acid because inductive electron withdrawal due to the amino group (containing the nitrogen) stabilizes the conjugate base. The weaker conjugate base leads to a stronger acid. C O OH C H 2 N H H amino acid, pKa ~2.3 C O OH C H H H carboxylic acid, pKa 4.76 C O O C H 2 N H H C O O C H H H Inductive electron withdrawal by the nitrogen atom makes the conjugate base of the amino acid more stable....
View Full Document

This note was uploaded on 05/31/2011 for the course CHEM 3341 taught by Professor Staff during the Spring '08 term at Georgia Southern University .

Ask a homework question - tutors are online