Determining Absolute Zero Using Charles' Law
To use Charles' Law to estimate the temperature of absolute zero.
- Heat the air in a small (125 mL) Erlenmeyer flask with a 1-hole stopper in a boiling water bath.
- Record the volume of air in the flask (V1) and the temperature of the boiling water bath (T1).
- Invert the flask into an ice water bath. (Water will come in through the hole in the stopper.)
- Record the volume of air in the flask (V2) and the temperature of the ice water bath (T2).
- Calculate your measured value of absolute zero graphically by plotting Volume (dependent, on theÂ y-axis) vs. Temperature (independent, on theÂ x-axis) and extrapolate the graph until it hits the x-axis (where V = 0).
For Honors Students:
- Calculate your measured value of absolute zero algebraically by usingÂ your two data points (T1,V1) and (T2,V2) to write an equation in yÂ =Â mxÂ +Â b format. Solve the equationÂ for x (temperature) where y = 0 (volume = 0) to get absolute zero.
- Calculate your expected value of V2 (which we'll call VE) from the formula VE = (V1)(T2)/(V1).
- Your % error is | VE - V2 | / VE x 100
Last modified: Sunday, 3 June 2012, 1:19 AM