I am performing the gas to rust: measuring the content of oxygen in air experiment but I do not understand the formula and how to analyze my results
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Gas to rust: measuring the content of air
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Re: Gas to rust: measuring the content of air
Hello!
In this experiment, the test tube is submerged in the water, creating a trapped air sample. The air in the test tube will only change by the iron rusting. To measure the oxygen content in this experiment (your results), you have to find the change in the volume of the test tube since the only reason the volume would change is due to a change in oxygen. As the iron uses oxygen in the reaction, the water level will rise in the test tube. This means the higher the water level, the more oxygen is used.
In the formula, the only variable you are changing will be the h (height). h is the total height of the test tube subtracted by the water level height, which is measured from the open end of the test tube to the water level. So even though your water level height is increasing, the total h used in the formula should decrease, thus decreasing your total volume as the oxygen is consumed. Once you have starting and ending volumes, you can subtract the two to see the change in volume (which represents the oxygen consumed in the rusting). To turn this into a percentage, you can calculate this by doing the (change in volume/initial volume) x 100. Based on your background research, you should have a basic idea of what the percentage should be and you can compare your data accordingly! If it is drastically different, there may be some sources of error to consider.
I hope that helps!
In this experiment, the test tube is submerged in the water, creating a trapped air sample. The air in the test tube will only change by the iron rusting. To measure the oxygen content in this experiment (your results), you have to find the change in the volume of the test tube since the only reason the volume would change is due to a change in oxygen. As the iron uses oxygen in the reaction, the water level will rise in the test tube. This means the higher the water level, the more oxygen is used.
In the formula, the only variable you are changing will be the h (height). h is the total height of the test tube subtracted by the water level height, which is measured from the open end of the test tube to the water level. So even though your water level height is increasing, the total h used in the formula should decrease, thus decreasing your total volume as the oxygen is consumed. Once you have starting and ending volumes, you can subtract the two to see the change in volume (which represents the oxygen consumed in the rusting). To turn this into a percentage, you can calculate this by doing the (change in volume/initial volume) x 100. Based on your background research, you should have a basic idea of what the percentage should be and you can compare your data accordingly! If it is drastically different, there may be some sources of error to consider.
I hope that helps!