Chemistry Unit 4

Course Overview

Throughout the ages people have relied on medicinal compounds derived from plants.  In this VCE Chemistry course students compare the general structures and reactions of the major organic families of compounds and deduce structures of organic compounds using instrumental analysis data.  Students who are unable to attend our onsite program can still complete (or complement) their VCE Chemistry SAC using this course. By watching a series of videos and completing accompanying activities, students will cover the same content.  Students also print out a double-sided worksheet to plot a line of best fit used to help determine the amount of active constituent in an analgesic tablet and show the relevant calculations.

PLEASE NOTE: Students booked for the onsite equivalent course at Ecolinc should NOT do this course as it repeats the content.

Background

Plants have throughout human history been used for medicinal purposes. The Chinese used tea from sweet wormwood leaves to cure chills and fevers, Egyptians used a brew from a plant called khella to help pass kidney stones. Bundjalung Aboriginal people from the coast of New South Wales crushed tea-tree (Melaleuca alternifolia) leaves and applied the paste to wounds as well as brewing it to a kind of tea for throat ailments.

Throughout the ages people have relied on medicinal compounds derived from plants. In medieval times people utilised a tea brewed from Willow bark to relive aches and pains. In 1763 the active ingredient of Willow bark was identified as Salicylic Acid. As an analgesic, salicylic acid is highly effective, however its tendency to cause stomach bleeding seriously limited in its usage. Felix Hoffmann, a chemist at Bayer, has been credited with the synthesis of aspirin in 1897. Aspirin (acetyl salicylic acid) tends to be less harmful than salicylic acid taken directly. Another derivative of Salicylic acid is its methyl ester, which is commonly called Oil of Wintergreen or simply Wintergreen.

Methyl salicylate is used as a liniment and is the active ingredient in products such as Deep Heat. Methyl salicylate and salicylic acid were originally derived from plants however in today’s world they are produced through chemical reactions utilizing base chemicals such as phenol, methanol and acetic anhydride.

Details

Prior Knowledge

This program will best suit students who have an understanding of basic organic chemistry, in particular, functional groups and IUPAC nomenclature.

Estimated duration

180 minutes

Learning Intentions

In this program, students will be able to:

  • identify functional groups and their reactions.
  • describe formation of esters
  • correctly identify key peaks in IR spectra
  • analyse data from HPLC to quantify active ingredients in analgesic tablets
  • see how chemical apparatus is used to correctly synthesize methyl salicylate

VCE Study Area

  • Unit 4 Outcome 1: Compare the general structures and reactions of the major organic families of compounds and deduce structures of organic compounds using instrumental analysis data.

Course Design: David Tait