Thursday 16 May 2013

4.11 describe simple calorimetry experiments for reactions such as combustion, displacement, dissolving and neutralisation in which heat energy changes can be calculated from measured temperature changes

Measure the temperature at the beginning of the experiment, measure the temperature at the end. How ever much heat has gone up or down is the calorimetry of the reaction.

For example if you have a beaker of water and take its temperature, then burn a piece of bread under it, the change in temperature is the calories (energy) of the bread.

5 comments:

  1. Surely the burning the bread will include a flame and won't the flame burning the bread heat the water and effect the experiment??

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    1. The way we did it at school was measure the temperature of the beaker of water, set a wotsit on fire using a flame away from the beaker, then when it was on fire put it under the beaker of water until it burnt out. We relit it again, then put it under a beaker as many times as it would take for it to not catch alight again, then measured the final temperature of the water. This way the flame's heat won't have affected the water

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    2. that is the idea- you measure the temp at the start of the experiment of the WATER, then you burn the bread as a fuel for the flame, you then see how much the temperature of the WATER changes, then from that you can see how much energy there is in the bread using the heat change.

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  2. I think the flame uses the energy from the bread to burn, when there is no more energy in the bread the flame stops burning. The bread's energy is the fuel.

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  3. The sun's energy heat's the bread and then it sends lunar radiation to kill everyone.

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