An experiment to measure the amount of oxygen bubbles given off in different strengths of sodium hydrogen carbonate
Equipment list
- Lamp
- Beaker
- Boiling tube
- Pond weed
- Ruler
- scissors
- Water
- Measuring cylinder
- Different strengths of NaHCO3
- Paper clip
- Stop clock
Plan
In the experiment I will get a piece of pond weed and cut it to 5cm I will then make sure that the hole is clear and the leaves from that end have been removed so that oxygen bubbles will be able to escape and not get trapped. Once I have done this I will attach a paper clip to the other end to keep the piece of weed in water or the solution. I will then get a beaker and put 200ml of water and into it. After this I would place the boiling tube with 40ml of water and the pond weed into it and turn on the lamp that will be put 20cm away from the beaker and leave for 3minutes so that the weed can get used to the water. Once these 3 minutes are over I will be taking readings on how many bubbles come out of the weed every 30 seconds and I will be taking ten readings. After I have took all these reading I will do the same again. But instead of the piece of pond weed being in water in will now be in 0.25% NaHCO3 and I will do the same leave it for 3 minutes so that the weed can get used to the solution and then I will start taking readings. I will take ten readings one every 30 seconds this will take me up to 5 minutes. After this I will do the same for 0.5%, 0.75% and 1.0% of NaHCO3 during all these experiments I will be using the same piece of pond weed.
This is a preview of the whole essay
Teacher Reviews
Here's what a teacher thought of this essay
This report of an investigation into the effect of changing carbon dioxide concentration on the rate of photosynthesis suffers, to some extent, from many of the common weaknesses that are to be found in a lot of GCSE coursework reports. It is worth highlighting some of these in the hope that students who read this essay might avoid making the same errors. [1] New science specifications are placing a clear emphasis on research skills and the ability to write scientific prose. In this report, the writer omits the introduction and plunges straight into the practical details. Students must make reference to previous work carried out by other scientists and evaluate its usefulness. [2] Every investigation must begin with a hypothesis linking IV and DV. To be fair, the writer does give a valid prediction with a clear trend stated. [3] Methods should be written in numbered stages, avoiding the use of 'I'. [4] Variables should be discussed at length with a clear indication as to how each one is to be controlled. [5] Conclusions should analyse data, specifically referring to number values and graph trends. [6] Evaluations need to seek out anomalous data, find reasons for it, discuss how it impacts on the conclusion, look at data reliability, and propose improvements to the methodology. In view of these weaknesses, this essay can only just be granted 3 stars and would be struggling to gain a C grade at GCSE. 3 stars
