Question

Why does the neutral compound, triphenylmethane, in this experiment fail to undergo reaction when treated with acid or base (consider the pKa of the neutral compound and acid/base equilibrium)?

29 Exp. No. Experiment/Subject Date Name Lab Partner Locker/ Desk No. Course & Section No. 1.5 9 of 1.17 Mix HA - AC Procedure Benzoic Alld (HA) B = base Ethyl-4-Aminobenzoate (B) N=neutral Tripheriyume thone (N) I 15 ML methylene chloride THA + B + N (organic layer) 16.15 mL 1 Add 4+ NaOH Check PH Jorganic layer (B+N) 4.5 mL I aqueous laver Add 3.00L HOLI contains sait of benzoic acid 166 H5600 Nat & CheckPH Trouma aqueous laver Add 5 mL laver contams salt of methylene chioride ripheint thane ethyl-4-aminobenzoate land HOLL (N) (B + HC1) Evaporate I OYOQIC aqueous Add 5mL TOVCI Triphenylmethane Taver contains meth viene chionne benzui ad Kontains Nach (НА) and NaOH & Evaporate [Benzoic acid (HA) organic laver Faqueous contam laver ethyl-4-aminon encoure Nach Evaporate Ethyl-4-aminobenzoate (B)

Answer 1

Triphenylmethane does not undergo reaction with acid or base because it is a hydrocarbon with three phenyl group. It is mostly stable de to presence of phenyl rings in which electrons delocalized. It does not have proton acidic enough to replace by base and form salt. Its pKa is around 33 and it remains in equilibrium with acid or base thus it remains dissolved in organic layer inspite of how much acid or base added to the system.