SCI121 Week 5

Answer all questions, using your textbook for help when necessary. 

Table 1: Temperature and volume data

PLOT AREA

(Insert a graph that you either drew here in Word or built from Excel using the data collected in this section)

Note:  On the graph, you are graphing volume on the y axis, temperature on the x axis. Use a line graph – nota bar graph.  You should have a linear graph, and if all goes right, you can extrapolate back so that the x axis is crossed at 0 K or -273 C.

This week you will explore how specific heat works and turn in your write-up by the end of the week. The lab for this week is “Lab 18, Experiment 2: Specific Heat”. Note that you do not need to complete Lab 18, Experiments 1 or 3 – only Experiment 2. Note that not all of the necessary materials for this week’s lab were included in your lab kit; you will need to provide your own ice and water.

Make sure to read through the entire introduction to Lab 18 prior to performing the experiment. You can access Lab 18 from the pdf document included in the Lab Manual CD-ROM, or download eScienceLabs Physics Lab 18.

Important Note: For this lab you will use the syringe included in your kit and test how the volume of a gas changes with temperature. The “screw” they refer to is the same as the cap that comes with the syringe. Just make sure this cap is on the syringe as you put it in the hot water.

Next, briefly take a look through the questions at the end Lab 18, Experiment 2. Enter all your responses into the following MS Word worksheet:

In your lab write up, support your observations and results with explanations using the scientific terms and theory we studied this week. Be sure to cite and reference all your sources, including the lab websites and additional readings.

You are now ready to start the lab! Make sure to follow the directions below when saving and submitting your work.

Questions:

1. What happened to the volume of gas when the syringe was submerged in each water bath? Using the concepts discussed above, describe why this occurs, keeping in mind the definition of temperature.

(Tip: Compare the volume of gas in hot water versus cold water and record your observation. Explain what you are seeing and why this is so.)

1. How do you know that pressure is held constant in your experiment?

1. Using a ruler, draw a straight line of best fit through your data points, extrapolating the line until it intersects the (negative) x-axis. Why can you assume a straight line, i.e., a linear relationship?

1. At what temperature does your line intersect the x-axis? What volume corresponds to this temperature?

1. Would it be possible to cool a real gas down to zero volume? What would most likely happen first?

1. Is your measurement of absolute zero close to the actual value (-273 °C)? How might you change the experiment to get closer to the actual value?

1. When does the gas in the syringe do work? When is work being done on the gas inside?