# Determining Absolute Zero Using Charles' Law

### Objective

To use Charles' Law to estimate the temperature of absolute zero.

### Plan

- 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 (
*V*) and the temperature of the boiling water bath (_{1}*T*)._{1} - Invert the flask into an ice water bath. (Water will come in through the hole in the stopper.)

- Record the volume of
in the flask (__air__*V*) and the temperature of the ice water bath (_{2}*T*)._{2} - 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 (
*T*,_{1}*V*) and (_{1}*T*,_{2}*V*) to write an equation in_{2}*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 V
_{2}(which we'll call V_{E}) from the formula V_{E}= (V_{1})(T_{2})/(V_{1}). - Your % error is | V
_{E}- V_{2}| / V_{E}x 100

Last modified: Sunday, 3 June 2012, 1:19 AM