1. Year 1 (Term 1) 2015 Joseph Rendall
Graphing Methods 2
Year 1 (Term 1) 2015
Joseph Rendall

2. To the computer lab
For a quicker method

3. Lab Notebook (Sections)
Introduction
Date, Statement of Purpose or Research Question, Source of Experiment
Experimental Plan
List of equipment and steps required to do the experiment. Safety requirements.
Observations and Data
Write down almost everything. Include your raw data tables.
Discussion of Results (Data Evaluation)
Thoughts on experiment, the results and possible future significances
Conclusion
Summarize the goal of your experiment and what was determined by the experiment

4. Lab Notebook (Sample Layout)
Title Date
Data
Introduction
2-3 sentences
Experimental plan
Construct pendulum as shown
Displace pendulum …
Observations
Lists and/or drawings

5. Lab Notebook (Sample Layout)
Discussion of Results
2-6 sentences
Conclusion
2-3 well constructed and succinct sentences

6. Hopes for the new process
You’ll understand physics better, be able to design your own experiments and write quality questions.

7. Measurements and Uncertainty/Error
All measurements include some uncertainty, it is the job of the scientist (or teacher-scientist) to identify the quantity of uncertainty in the measurement and identify what types (quality) of error there are in the experiment.
Types of error or uncertainty
Systematic
Biases data in one direction
Human
We all make mistakes (transposing numbers, ect.)
Random
Doesn’t bias data in any direction
When data is averaged the results will be accurate but not precise
Instrument precision
Sensitivity of instrument
Activities

8. Year 1 Pratical Exams (Challenges and Tips for passing)
Hardest part is knowing “what the question asking!?”
Ask for all things to be clarified!
Exam time management skills
Some exams are packed with information
Rewriting data tables and graphs can cause you to loose valuable time
Don’t cross out bad work until you have replaced it with good work
Be sure to attempt all parts of questions
Hands-on skills
Make sure during labs you get a chance to manipulate the apparatuses
Be exacting but efficient in your handing of the apparatuses
Units
Know your units or how to determine them

9. Reports for Lab’s Include
Title
Introduction (Background of Physics Topic and Experiment)
Methods (Description of Experiment, Sometimes Raw Data)
Results (Tables and Explanation)
Conclusion (Significance of Results)
Discussion (Future Research)
References

10. Handout
Questions
Thoughts
Think Pair Share

11. Example Intro.
The objective of this lab was to determine the energy involved in the phase changes of ice, water, dry ice (sold CO2), and liquid nitrogen. By placing two substances in contact with each other – by placing them in an insulated container – heat energy is transferred from the warmer substance to the cooler substance. The energy change of the first substance can be calculated from its mass m, temperature change (delta t), specific heat s, according to the equation q = ms(delta t). If the system is well insulated then the energy change of the second substance can be assumed to be equal, but opposite in time – thus all energy is conserved. 

12. Example Intro.
A procedure utilizing this information was used to determine the energy involved in the phase changes of ice water, dry ice, and liquid nitrogen. The expected result for the experiment would be that CO2 requires the most energy since it is going from solid to a gas (sublimation). As for water and nitrogen, they would be around the same amount of energy since fusion and vaporization – only changing by one state in matter. This experiment is important because phase changes are prevalent in chemistry, and one should be aware of the energy associated with them. 

13. Example Methods Part 1 1) 25 ml of water was heated.
2) The weight was measured.
3)20 grams of ice was added.
4) Using the probe, the initial value was recorded.
5) The ice was added to the water.
6) When all the ice melted and the temperature started to increase, the T was recorded.
Part 2
Similar to part one, but 40 g of liquid N2 was added.
Part 3
Similar to parts one and two, but 15 g of dry ice(CO2) was added.

14. Example Data Mass and temp hot water: Mass and temp solvent:
50g at 70 C 20g at 0 C
46.51g at 53 C g at -196 C
51.37g at 63 C g at -78 C

15. Example Results

16. Example Results

17. Example Conclusion
The energy involved in the phase change of liquid nitrogen to gas was 6.12kJ/mol, the energy change of solid CO2 to gas was 27.04kJ/mol, and the energy change associated with the change from ice to liquid was 572kJ/mol). These results were found by measuring the heat transferred from the first substance to the second substance, assuming minimal energy loss to the surroundings. In this lab, the concepts of conservation of energy and specific heat were utilized in order to calculate phase changes, and enhance one’s understanding of how energy is associated to changes in matter.

18. Example Discussion
The results give the change in heat of a substance by knowing the specific heat of water and the starting temperatures of the two solutions. This can be done for most mixable substances where the boiling temp and freezing temp are known. These temperatures and masses lead to knowing the change in energy of the mixing. There could be a large source of error in the water ice part of the lab because the amount of water was poured in was measured in a beaker, not weighed like the parts for dry ice and N2. The last 2 parts of the lab turned out with very low percentages of error. (mainly doing to the weighing of the hot water added)

19. Example References