during a molar volume of oxygen experiment indicate how each of the following errors would affect (increase, decrease, or no change) your calculated value for the molar volume of O2 at STP.
1.) Your sample was not completely decomposed.
2.) After you finish heating sample & the system cooled to room temperature, you closed the clamp on tube D without re-equalizing the pressures inside and outside of the flask, The water in beaker E was 4 inches deep & the water in flask C was 2 inches deep.
I don't know every step you followed; therefore, I'm hesitant to get into detail but here is what you should do.
Make list on a page of each step you followed. Beside each step, place the calculation formula used for that step. Then analyze each step, take the results and go to the next step until you get to the end.
Here is an example.
Suppose we standardize a NaOH solution with KHP (potassium hydrogen phthalate).
1. Weigh KHP primary standard.
2. moles KHP = grams KHP/molar mass.
3. Titrate KHP with NaOH.
4. Record mL NaOH.
5. Calculate M NaOH from mL NaOH x M NaOH = moles KHP
Now the problem might say, "We weigh the KHP but a small amount of KHP did not get transferred to the titration flask and we didn't notice it. What is the effect on M NaOH?"
Ans: grams KHP is too high which makes moles too high from step 2. Larger KHP moles in step 5 gives M NaOH too high.
I hope this helps.
1.) If the sample was not completely decomposed, it would likely decrease the calculated value for the molar volume of oxygen at STP. This is because the incomplete decomposition means that not all of the oxygen gas produced will be collected. As a result, the measured volume of oxygen collected would be lower than it should be, leading to a lower calculated molar volume.
2.) Closing the clamp on tube D without re-equalizing the pressures inside and outside of the flask, and having different water levels in beaker E and flask C, would also affect the calculated value for the molar volume of oxygen at STP. This is because there would be a difference in pressure between the inside and outside of the flask, which would affect the volume of gas collected. The difference in water levels could create a pressure difference due to the different hydrostatic pressures.
The specific effect on the calculated value would depend on the magnitude of the pressure difference and the difference in water levels. In general, however, it is likely that the pressure difference would increase the volume of gas measured, leading to an increase in the calculated molar volume of oxygen at STP.
To help answer your question, let's first understand the concept of molar volume of oxygen at STP. The molar volume of a substance is the volume occupied by one mole of that substance at a specific temperature and pressure, typically at Standard Temperature and Pressure (STP) which is defined as 0 degrees Celsius (273 kelvin) and 1 atmosphere of pressure.
1.) If your sample was not completely decomposed:
In this case, the incomplete decomposition of the sample means that not all of the oxygen gas was released. This error would lead to a decrease in the calculated value of the molar volume of oxygen at STP. The calculated value would be lower than the actual value because some oxygen molecules would still be trapped in the sample.
To minimize this error, it is important to ensure that the sample is thoroughly decomposed before measuring the volume of the released gas. This can be done by heating the sample for an appropriate amount of time to ensure complete decomposition.
2.) If you closed the clamp on tube D without re-equalizing the pressures inside and outside of the flask:
In this situation, the water levels in beaker E and flask C act as barriers preventing pressure equalization between the inside and outside of the flask. This error would have an impact on the pressure measurement.
If the pressure inside the flask (due to the released oxygen gas) is higher than the atmospheric pressure outside the flask, closing the clamp without equalizing the pressures would result in a decrease in the calculated value of the molar volume of oxygen at STP. The reason is that the pressure inside the flask is higher than it should be, affecting the measured volume of gas. This would lead to an underestimation of the molar volume.
To avoid this error, it is necessary to ensure the pressure inside the flask is equalized with the atmospheric pressure by adjusting the water levels in beaker E and flask C. This can be achieved by raising or lowering the water levels until they are equal, allowing for proper pressure equalization.
Keep in mind that uncertainties and errors in experiments are common. To minimize them, it is important to follow proper experimental techniques, ensure complete reactions, measure accurately, and take into account any potential sources of error.