Practical

Weigh out drying agent and record to a precise amount. Place 25cm3 of deionised water into a polysterene cup and record initial temperature. Start timer and record temp for first three minutes. At the fourth minute, add first reagent and began recording in minute intervals at 5 minutes again. Stir continuously as this occurs and a lid may prevent heat loss.

Add 10cm3 of HCl to a test tube Add 10cm3 of sodium thiosulfate to a test tube with a black X cross under it. Carefully insert thermometer and record initial temperature. Add 1cm3 of acid to test tube and start stopcock. Record time taken for X to disappear Record final temperature and pour into sodium carbonate solution to prevent SO2 Do at different temperatyre by warming with a water bath

Acidify the potassium manganate(VII) solution combining a volume of a regular laboratory concentration with an equal volume of dilute sulfuric acid. Pour the mixture into a pear-shaped/round flask, with a still head containing a thermometer. Attached to a condenser with a ice cooled collecting vessel. Add a few anti-bumping granules. Heat the flask gently. Collect sample at boiling point of the desired product. The cooled collection vessel is essential to reduce evaporation of the product.

Add 50cm3 of 0.8 HCl to a conical flask. Set up gas syringe equipment. Add a 6cm strip of Mg ribbon to a conical flask, place the bung firmly on top of the flask. Record volume of H gas every 15 seconds for 2.5 minutes. Alter HCl concentration and repeat steps.

Crush an aspirin tablet with pestle and mortar. Transfer to a weighing boat or bottle. Dissolve approx 0.1g of the powdered tablet in 0.5 cm of ethanol. Repeat with other painkiller tablets.

Prepare a beaker with a small quantity of solvent On a TLC plate, draw a horizontal line at the bottom edge (in pencil) Place a spot of pure reference compound on the left of this line, then a spot of the sample to be analysed to the right of the baseline and allow to air dry Place the TLC plate inside the beaker with solvent and place a lid on top Take out before solvent reaches the top and draw new pencil line

Put the distillate of impure product into a separating funnel Add saturated sodium chloride solution Allow layers to separate in funnel, and then run and discard the aqueous layer Run the organic liquid into a clean, dry conical flask and add 3 spatula loads of drying agent Carefully decant the liquid into the distillation flask Distil to collect pure product

Dissolve the impure compound in a minimum volume of hot (near boiling) solvent Hot filter solution through (fluted) filter paper quickly. Cool the filtered solution by inserting beaker in ice. Suction filtrate with a Buchner flask to separate out crystals. Wash the crystals with distilled water Dry the crystals between absorbent paper.