Kiyah adds 10 mL of hydrochloric acid to the reaction solution, tests the pH, and...

Kiyah adds 10 mL of hydrochloric acid to the reaction solution, tests the pH, and observes a
yellow-green color on her pH paper. She then adds 5 mL of hydrochloric acid to her solution,
tests the pH, and observes a dark red color on her pH paper. She isolates her pure vanillyl
i. Explain the reason behind Kiyah’s lower yield from the scenario above.

ii. Molecularly, why does this happen?

iii. The work up step is a critical step in synthesizing and isolating vanillyl alcohol. What
is a good indicator to stop adding hydrochloric acid?

(b) At the start of lab, Anthony adds vanillin to his Erlenmeyer flask, then adds sodium
hydroxide, and lets the suspension cool.
i. With pictures and minimal words, identify the reaction that takes place between
sodium hydroxide and vanillin.

ii. Is sodium borohydride capable of inducing the same reaction as (i)? Explain.

(c) During the recrystallization step, Bailey sets her flask with crude vanillyl alcohol and flask
with ethyl acetate on the hot plate and begins heating. She waits until the ethyl acetate is
boiling and recrystallizes her product. Later, she notices that her product looks different
than her peers. She also recovered little vanillyl alcohol.
i. Identify the error that Bailey made with recrystallization that caused these ending
discrepancies.

ii. In this experiment, name one technique of recrystallization that can result in a
larger vanillyl alcohol yield. (Hint: Minimizing solvent is not an answer)?

1 Answers Available
Asked by Tyhj on 13th July, 2022