Experimental Techniques in Chemistry

Teacher's Guide

Video Programmes

(The following videos are streamed for playback using Windows Media Player version 7 or above with a transmission speed of 100 k bits / second.)

Flame Test (4.5 mins)

Equipment for flame test; Cleaning a platinum wire; conducting the flame test; comparing the characteristics flame colours of sodium and potassium; flame colours of stronium, barium, lead, iron, calcium and copper.

Using Quickfit Apparatus (8.5 mins)

Sealing a quickfit joint by lubricant; equipment for distillation; assembling the quickfit; Transferring chemicals to reaction flask; placing thermometer bulb in the correct position; setting up a water condenser; using a T-shape adapter; adding anti-bumping granules before heating; adjusting the rate of heating; other methods of heating; dismantling quickfit apparatus.

Acid-base Titration (Hydrochloric acid against sodium carbonate) (19 mins)

Dissolving the solute in a beaker; transferring the solution to the volumetric flask; making up the mark; homogeneous mixing of the prepared solution; rinsing a burette with distilled water; rinsing a burette with titrant; filling a burette with titrant; rinsing a pipette with distilled water; filling a pipette; delivering liquid from a pipette; carrying out the trial titration; doing a more accurate titration.

Extraction of Active Ingredients in Aspirin Tablets (12.5 mins)

Using a mortar and pestle to grind solid into powder; folding a fluted filter paper; dissolving the aspirin powder; filter a hot and saturated solutions; crystallization; carrying out suction filtration; taking solid out from the Buchner funnel; preparing a melting point tube; introducing solid into a melting point tube; using a melting point apparatus to determine the m.p. of a purified solid.