Unit 2- Practical Scientific Procedures and Techniques
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Calorimetry and substance cooling curves - Unit 2 assignment 3 Methodology
Both experiments follow the same process, with the difference that the steric acid is heated to 90°C
while the paraffin wax is heated to 80°C. Begin by gathering all of the essential supplies. A boiling
tube containing 10g of the item to be cooled (paraffin wax / steric acid), a water bath with boiling
water, a clamp stand for the cooling stage, a valid thermometer for the experiment, and a timer for
the experiment are all required.
Begin by boiling some water to provide a suitable water bath for the experiment. After the water
bath is ready, get 10g of the substance you'll be using for the experiment. I didn't have to weigh out
10g of paraffin wax and steric acid for my experiment because they were already within the boiling
tube, allowing me to dedicate more time to it. If you're conducting many experiments with different
chemicals at the same time, mark the boiling tubes so you know what's in each one. In the boiling
tube, then in the water bath, place the thermometer. Wait for the thermometer to achieve the
required temperature for the experiment. Paraffin wax requires an optimal temperature of 80°C,
while steric acid requires a temperature of 90°C. After the boiling tube has attained the desired
temperature, remove it from the water bath and suspend it in a clamp support. Wait until the
temperature reaches the exact setting you desire. After you've attained the appropriate
temperature, start the timer and record in 20 second intervals. Keep rotating the object while
recording the temperature while it's still liquid. This is because it reduces the number of hotspots
recorded by the thermometer. Heat is evenly diffused when whirling, allowing for exact temperature
readings. When a hotspot is found, it may cause a rapid spike or fall in temperature, which might
affect the final results. Take temperature readings every 20 seconds until you achieve the needed
temperature to complete the experiment. At 40 degrees Celsius, paraffin wax melts, while steric acid
melts at 45 degrees Celsius. After you've achieved the end temperature of your material, you may
stop the experiment and analyse the cooling data. You can now use this data to determine the
average rate of cooling and generate a graph to represent the cooling of a material. If you think your
results are wrong because they show a lot of fast temperature swings, repeat the experiment until
you see trends and patterns that prove your data is right. Because I didn't have enough time to do
both the paraffin wax and steric acid tests, I only did the experiment once. If you need to repeat the
experiment, use the same object in the boiling tube and reheat it to the desired temperature.
Because the temperature has decreased to room temperature, you'll need to re-boil your water.
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