Provide Evidence in a Prosecution Case
Experiments to Provide Evidence in a Prosecution Case with the Pervis Vinegar Company on Unknown Toxins
The aim of this experiment is to preform tests on two samples of vinegar, one that is commercially safe and the other not (from the Pervis Company) to determine the unknown toxin contained in the Pervis Vinegar.
* Numerous Beakers/Conical Flasks
* Phenolphthalein Indicator
* Numerous Test Tubes
* Sticky Tape
* Test Tube Rack
* Sodium Hydroxide (NaOH)
* Sample of Commercially Safe Vinegar
* 2 Surgical Swabs (large cotton bud)
* Sample of Pervis Vinegar (Toxic)
* 2 Agar Gel Plates
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This was completed three tines with the average NaOH needed to neutralise the safe vinegar approximately 154.5 ML. These amounts for the NaOH added were then recorded for later analysis. The pH test was now done with both samples of vinegar. Two test tubes were placed in a test tube holder and 14ML of each sample of vinegar poured into one of the test tubes. About two drops of Universal Indicator were placed in the test tubes and the reaction colourers were recorded for later use.
The next experiment was to place a small amount of each sample of vinegar into their own Agar plate to see if any bacteria growth in the Pervis sample. Two syringes surgical swags, Agar plates, and a roll of sticky tape were collected. The surgical swabs were unwrapped from their sealed sterile packages and now both syringes were full of the two samples of vinegar. Each surgical swab had injected on it, a reasonable amount of vinegar from the syringe and this occurred with both samples. One surgical swab was then spread across the surface of one of the Agar plates in a 'zig zag' fashion. This also occurred with the other sample although it was placed in a separate Agar plate. Both plates had their lids sealed with sticky tape to ensure no potential pathogens or other organisms were released. Both plates were then placed in an incubator for 5 days at approximately 37ºC.
The final experiment was to ascertain whether the Pervis vinegar had any Lead in its sample. To find this out a precipitant test for Lead was used which needed water, HCl, Potassium Chromate Solution and a Bunsen burner. A small amount of each sample was put in a test tube and then a few drops of HCl were added. 20MLS of water was then added to each test tube and then both test tubes were boiled under a Bunsen burner. Then 10MLS of Potassium Chromate solution were added to each sample and at that point the Pervis sample reacted with a yellow precipitant while the other sample only be came yellow coloured.