Question

Chem 181 Working With Numbers 7. When studying gases, Irish chemist Robert Boyle noticed that as he changed the pressure, the volume of a gas would also change. The following data represents what Boyle may have observed: Pressure, 0.100 0.250 0.360 0.420 0.600 0.900 atm 3.670 Volume, 1.402 10200 880 0615 0.400 0.330 | 1.10 Inverse, 1/y a. Which is the dependent variable? Explain your answer. b. When plotting pressure and volume, the results do not product a straight line; however, taking the inverse of the dependent variable (inverse = 1/y) gives much more linear data. Use Excel to calculate these inverse values and enter them in the above table. C. Plot the inverse of the dependent variable vs. the independent variable in Excel or a similar spreadsheet program and give the equation of the best-fit line and R2 value. d. Print a copy of your properly formatted, titled graph to hand in with this post-lab report.

Answer 1

(A) If the volume is labeled for the x-axis, then that makes it the independent variable here; that is to say, we're changing the volume to measure the pressure:

Pressure Volume

However, this graph would look exactly the same if pressure were the independent variable; i.e. we're changing the pressure to measure the volume:

Volume V Pressure P

It really all comes down to which variable you're changing and which one you're measuring. more often, pressure will be measured against volume, so volume would then be in the x-axis. so volume is our independent variable.

(B)

1/y=1/p

10

4

2.77

2.38

1.66

1.11

0.9

(C)

ه2 ,7 3 . 5 و )

(D)