PL - Equilibria (acid–base) *01 *02 Flashcards
carboxylic acids - functional group
contain the carboxyl group (-COOH)
dicarboxylic acid - functional groups
contain two carboxyl groups at either end of the molecule
carboxylic acids - strong or weak acids
weak acids
they partially dissociate into carboxylate ions (R-COO-) and H+
carboxylic acids - reaction with metals
react with more reactive metals in a redox reaction to form a salt and hydrogen gas
carboxylic acids - reaction with carbonates (CO3^2-)
reacts with carbonates to form a salt, carbon dioxide and water
carboxylic acids - reactions with aqueous alkalis
react with aqueous alkalis to form salts and water
PAG 7
what can amino acids exist as ?
zwitterions
what is a zwitterion?
an overall neutral molecule that has both a +ve and -ve charged in different parts of the molecule
can only exist as a zwitterion near its isoelectric point - the pH where the overall charge on the amino acid is zero, this depends on the R-group.
structure of zwitterions - in conditions more acidic than isoelectric point
H3N+ - CH(R) - COOH
structure of zwitterions - in conditions more basic than isoelectric point
H2N - CH(R) - COO-
structure of zwitterions - at isoelectric point
H3N+ - CH(R) - COO-
amino acids - amino (amine) group nature
basic because the lone pair on the nitrogen (NH2), can accept a H+ ion to give N+H3
how do amino acids react
the amino group of one amino acid reacts with the carboxyl group of another
forms a peptide link
condenstation reaction to make