Our experiment will be repeated three times, and we will use the same stopwatch. We will place the candle onto the safety mat and light it. Carefully, one of us will cover the lit candle with the beaker, whilst the other shall start the stopwatch. As soon as the candle goes out the stopwatch shall be stopped, measured and the result will be recorded into the results table. This shall be repeated two more times for the same beaker and the results will also be recorded into the results table. We will carry out this method four more times for the measured beakers, and then we will do the same with the Gas Jar.
The difference in method between the Gas Jar and the other beakers is that we know the volumes of the other beakers, but the volume of the Gas Jar is unknown. For the Gas Jar, we will put a candle onto a safety mat, light it, and then cover it with the Gas Jar. We will start the stopwatch and record how many seconds the candle is lit for. As soon as the candle goes out, the stopwatch will be stopped. We will record the amount of time the candle is lit for, into the results table. Then I will find the average result of the three tests for each beaker.
I will find this by using this formula. This average will then be recorded into my results table. Then I will draw my graph. On my graph, the seconds will be on the “y” axis and the volumes of the beakers will be on the “x” axis. I will plot all of my results onto my graph and measure a line of best fit. On the line of best fit will be all of the approximate results of the seconds the candle is lit for, for all volumes of beakers. To find the volume of the gas jar, I will plot the time that the candle was lit for on the line of best fit.
Then I will follow my finger from the line, horizontally, to the “y” axis, and see what the approximate volume of the Gas Jar is. Results TIME CANDLE IS LIT FOR (s) Volume of Glass Beaker (cm 3) Test 1 Test 2 Test 3 AVERAGEAnalysis From my results I have found out the Gas Jar has an approximate volume of 200 cm cubed. I conclude that it is possible to find out the volume of a beaker when all you know is how long a candle burns for when it is placed underneath.
The graph proves my prediction to be correct. I said that the larger the beaker, the longer the candle will burn for, which would then give my graph a positive correlation. This is what happened. When the size of the beaker went up, so did the amount of time the candle beneath it. There was a relationship between the variables I was measuring – The larger the Beaker, the longer the candle will burn for. I proved that there is more oxygen in a large beaker than a small beaker, as the small beakers candle did not stay lit for as long as a larger beakers candle.
Evaluation I have achieved the aim that I wrote at the beginning of my experiment. I have found out whether it is the candle or the size of the beaker that determines how long the candle burns for. I have also found out that you can determine the volume of a gas jar, just by timing how long the candle burns for when placed underneath. My plan was quite good. I have achieved all that I wanted to achieve, and found out all that I wanted to find out. I have gained everything from my experiment that I had aimed to gain, and without any problems.
I don’t think that I could have changed anything to make it better, except to maybe do more tests to get my average from, because they will, of course, be more accurate. I didn’t change anything to make anything work better, it already worked perfectly fine. My results were very good, all of my results were consistent as they were quite close to each other. Also they followed my prediction perfectly, I had no problems. From my results I have calculated that the Gas Jar had an approximate volume of 200 cm cubed. The actual volume of the gas jar is 210 cm cubed.
This result is extremely close to my approximation, which means that my results were very accurate. I also believe that my experiment was a very fair test, we followed our method exactly and had no reason to change anything. I think that my results were pretty reliable. There was an obvious line of best fit in which many of the results fitted in with. I did have one anomalous reading though, but it was not far off track. An Anomalous reading is a reading that didn’t follow the same pattern as the others. This might have occurred because of a number of reasons.
For example, We could’ve made an error in taking measurements or we might not have filled up the gaps in the beaker enough etc. I think, that by carrying out a further experiment, we would extend our knowledge by changing the experiment a little, by maybe changing a different variable or by having more tests. Either way, we would learn a lot more on this specific subject. Katrina Farrant 10HA Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.