Apparatus List.
v Test Tubes (x 10) .
v Test Tube Rack.
v Large Beaker.
v Bunsen Burner.
v Tripod.
v Rubber Bung.
v Gloves.
v Goggles.
v 10cm Measuring Cylinder.
v Teat Pipette.
v Thermometer.
v Microscope.
v Slides And Cover Slips.
Materials.
v Lead Nitrate - Pb (NO3)2.
v Potassium Chromate - K2CrO4.
v Lead Ethanoate - Pb(CH 3 COO).
v Sodium Chromate - Na2CrO4.
Method used.
For my experiment I decided to investigate the effects of temperature on Lead Nitrate and Potassium Chromate. I set up the Bunsen burner and put a large beaker with water on it. I then placed a thermometer in the water to check what the temperature of the water was. It was already 20 ∘C so I then put 5cm of Lead Nitrate and Potassium Chromate in a text tube, corked it and placed it in the beaker after shaking it. I repeated this process using different temperatures (20 ∘C, 30 ∘C, 40 ∘C, 50 ∘C, and 60 ∘C). After I had done this, I repeated the experiment using different materials so I could compare them. For this I used Lead Ethanoate and Sodium Chromate and recorded the results. I labelled the text tubes as I was doing the experiment with an appropriate hazard warning. .
Results - Table 1: Shows the temperatures and description of the experiment with Lead Nitrate and Potassium Chromate.
Temperature in ∘C Description of reaction.
20 ∘C At 20 ∘C the pigment had changed to a bright yellow colour, just as it would at regular room temperature. Once it settled, large crystals had formed with a clear liquid at the top.
30 ∘C Very similar to 20 ∘C however this time round the pigment changed to a lighter shade of yellow. When it was settles there was an almost clear liquid, which had formed at the top.
40 ∘C When heated to 40 ∘C the liquid became noticeable darker and larger crystals had been solidified. The liquid, which had been quite clear at the previous heats, remained the same.
