moved into the flask from the total volume of the flask . This is the volume of the gas inside the flask after cooling .
20 . Your data table should look something like this :
Data Points
Temperature in Celsius
1 ( record temperature of the flask in the boiling water )
2 ( record temperature of the ice bath )
Volume in mL
( total volume of flask )
( total volume of flask minus volume of water that moved in )
21 . On your graph , temperature should be on the x-axis . The range of temperatures should be from -300 to about 150 degrees C . Volume in mL should be on your y-axis . The range of volumes should be from 150 mL to 0 mL .
22 . Plot your two points .
23 . Using your ruler , draw a straight line between them .
24 . Line up your ruler with the line you already started . Make a dotted line extending the line you drew all the way to where the volume is equal to 0 on the x-axis .
25 . Carefully determine the temperature , where your line crosses the X axis . This is your determination of absolute zero !
Results
The expected value for absolute zero is -273.15 C . If your value falls between -250 C and -300 , you did well considering the limitations of your equipment and graph paper .
Volume
Temperature ( K )
Why ?
SCIENCE PROJECT
WINSPIRE : Empowering youth | December , 2016
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Materials required
All the glass materials must be made of some sort of Pyrex-like material , to prevent shattering during temperature changes .
• Bucket • Ice • Big spoon
• Water • Safety goggles
• 125 mL Erlenmeyer flask
• Large beaker , at least 500 mL
• One-hole rubber stopper that fits the 125 mL flask
• Short glass rod ( 5- 10 cm ) that fits snuggly into the stopper hole
• Ring stand • Clamp • Hot plate
• Tongs big enough to hold the 125 mL flask • Celsius thermomete
• Graduated cylinder • Graph paper
• Ruler
• As you cooled the flask in the ice bath , the molecules of gas inside the flask moved around less and less . The gas molecules took up less space inside the flask , so water from the outside slowly moved in . Charles ’ law predicts that as the temperature decreases , the volume also decreases .
• Another important concept related to gases , pressure and temperature is Gay-Lussac ’ s Law : the pressure of a fixed mass of a gas at a constant temperature varies directly with the temperature . The
P equation for this relationship is =
2
T 1
T . 2
You might remember that the pressure of a gas is the amount of force exerts per unit of surface . An example of this phenomenon is when the lid of a plastic container pops off when you heat it in a microwave . The temperature is going up , but the volume of the gas remains the same because the lid . Pressure therefore increases with temperature until it is high enough to pop open the lid .
P 1