A3 Summative Practical 2: Molar Volume of a Gas Practical
Introduction
1. Student should have written on the criteria’s set for them. We need to read their work and just make sure everything is factually correct. Please ensure that they included in-text citations for their work, if they fail to comply minus 1 mark ONCE if they did not cite their work. Please copy and put the following comment:
All factual information needs to be accompanied by in-text citation (Criteria 1: minus 1 mark)
2. If a student has large section of work poorly paraphrased (at least 2 lines highlighted) put the following comment:
It appears that large part of this section is poorly paraphrased, please paraphrase all your future work by reading the information and synthesising your own words (Criteria 1: minus 1 mark)
3. If the information given is insufficient (use your own discretion) then include any one of these comments:
The introduction lacks sufficient information to fully describe the difference between the behaviour of ideal gases and real gases. (Criteria 5: minus 1 mark)
The introduction lacks sufficient information to fully describe the conditions under which real gases come close to the behaviour of ideal gases. (Criteria 5: minus 1 mark)
The introduction lacks sufficient information to fully explain the rational for the additional parameters present in the Van der Waals equation application of the ideal gas law (Criteria 5: minus 1 mark)
Aim
The sentence does not describe the aim of this experiment. (Criteria 1: minus 1 mark)
Equipment and Chemicals
These were not required and you were informed about it. (Criteria 1: minus 1 mark)
Procedure
These were not required and you were informed about it. (Criteria 1: minus 1 mark)
Results
1. The title of the table is missing (Criteria 2: minus 1 mark)
2. The title is does not describe the contents fully (Criteria 2: minus 1 mark)
3. Mass of magnesium should be only 2 significant figures (Criteria 2: minus 1 mark)
4. Volume of hydrogen should only be 2 significant figures (Criteria 2: minus 1 mark)
Data Analysis and Discussion
Please allow for error carried forward
1. Equation not balanced (Criteria 3: minus 1 mark)
States of matter not stated or at least two of them have an error (Criteria 3: minus 1 mark)
2. From your results:
a Show how you calculated the average volume of hydrogen collected
Calculation not shown (Criteria 3: minus 1 mark)
b Show how you calculated the average mass of magnesium used
Calculation not shown (Criteria 3: minus 1 mark)
c From the answer in (b) show how you calculated the average moles of magnesium that has reacted
Calculation not shown (Criteria 3: minus 1 mark)
d Identify the limiting reactant
Calculation not shown (Criteria 3: minus 1 mark)
Wrongly determined the limiting reactant (Criteria 3: minus 1 mark)
e Determine moles of the excess reactant which is left behind
Calculation not shown (Criteria 3: minus 1 mark)
Wrongly determined the moles of the excess reactant (Criteria 3: minus 1 mark)
f Calculate the theoretical moles and the theoretical volume of hydrogen
Calculation not shown (Criteria 3: minus 1 mark)
Wrongly determined the moles / volume (Criteria 3: minus 1 mark)
g Using the average volume of hydrogen, you collected during the experiment and the volume calculated in part (f) calculate the % yield of this experiment.
Calculation not shown (Criteria 3: minus 1 mark)
Wrongly determined the % yield (Criteria 3: minus 1 mark)
3. Using the volume of hydrogen, you collected in this experiment at 298K and 101.3 kPa
a Name the gas law that you will use to solve this question
Name not provided or it is wrong (Criteria 3: minus 1 mark)
b Calculate the volume of hydrogen that will be collected if the experiment was done at Standard Temperature and Pressure (STP) i.e. 273K and 100kPa.
Calculation not shown (Criteria 3: minus 1 mark)
Wrong volume determined using an unknown method (Criteria 3: minus 1 mark)
c Hence, calculate the molar volume of hydrogen collected at STP
Calculation not shown (Criteria 3: minus 1 mark)
Wrong molar volume using an unknown method (Criteria 3: minus 1 mark)
4. Using the ideal gas equation (PV = nRT), and the data from 3c. determine an experimental value of the gas constant, R at STP. Use the correct number of significant figures.
Calculation not shown (Criteria 3: minus 1 mark)
Wrongly determined the R value using an unknown method (Criteria 3: minus 1 mark)
5. Compare your result for the molar volume of hydrogen and the R value at STP with the accepted molar volume of an ideal gas, 22.7 L/mol and R which is 8.314 kPaLmol-1K-1? Suggest two reasons for any difference.
The reason provided does not explain the results, it does not clearly explain to the reader why your molar volume or the R value was higher / lower than expected. (Criteria 3: minus 1 mark)
The reason provided does not clearly describe the difference in the result (Criteria 3: minus 1 mark)
Conclusion
Write a conclusion for the experiment that summarizes the findings and responds back to the aim.
The conclusion does not link back to the original aim of the experiment. (Criteria 5: minus 1 mark)
References
Include citation of references for this report using the APA referencing system and list the references at the end of the report.
Reference list is missing (Criteria 5: minus 3 mark)
Only one reference out of three (Criteria 5: minus 2 mark)
Only two reference out of three (Criteria 5: minus 1 mark)
Reference does not follow the APA format, or there is no attempt to present reference in a format close enough to be considered APA. (Criteria 5: minus 2 mark)