1.
Part 2 (2.3 points) Feedback Which of the following item(s) explain the differences between the
Ka values. Choose one or more: A. The oxidation state for oxygen in trifluoroacetate is more
negative than the oxidation state for oxygen in acetate. B. The trifluoroacetate molecule has more
resonance structures than the acetate molecule C. The electron-withdrawing fluorine atoms pull
electron density from the oxygen in trifluoroacetate. The negative charge is more stabilized in
trifluoroacetate by this effect D. The negative charge is on the more electronegative fluorine
atom in trifluoroacetate.
Solution
Answer
C) The electron-withdrawing flourine atoms pull electron density from the oxygen in
triflouroacetate.The negative charge is more stabilized in triflouroacetate by this effect.
Explanation
Ka value of triflouroacetic acid is higher than Ka value of acetic acid, this indicate trichloroacetic
acid is stronger acid than acetic acid.
For acid to be more stronger the conjucate base of the acid should be more stabilised
triflouroacetate ion and acetate ion both are resonance stabilised but triflouroacetate ion having
extra stability because more electronegative fourine atoms pull electron density from oxygen
atom, so, electron density of oxygen in triflouroacetate ion is shared between atoms thus the ion
become more stabilised.