Question

Let's say we have one chemical that is suspected to be "L-proline" (C₅ H₉ NO₂) . Given the reagents 7 unknown chemicals, dH20, iodine, dilute HCI solution, dilute NaOH solution, and isopropyl alcohol, How do one confirm the chemical identity? I'm asking this because I have to make our own lab protocol to confirm the chemical.

Answer 1

Proline is amino acid which contains -COOH group, as we know carboxylic acid react with sodium hydrogen carbonate liberating carbon dioxide

In the above chemicals only dilute HCl and Proline reacts with sodium bicarbonate

Prepare a standard solution of NaOH and titrate with two Unknown solution Proline and HCl

Plot a graph of pH versus volume of NaOH

For Proline

P^H = P^ka + log ([salt ]/[ acid ])

At equivalent point [salt ] = [ acid ]

P^H = P^ka

by knowing P^ka it is possible to identify acid