Title of Lab: Gas Laws II
Name: ____________________________ block _____________
Information: Temperature changes will have an effect on both volume and pressure. In this lab you
will explore this relationship by using the combined gas law:
P1V1 = P2V2
T1
T2
Hazard: Minimal. Balloon could pop due to overinflation.
Materials: 2 – 500 or 700 mL beakers, water, crushed ice, 1 small balloon, thermometer, timer (cell phone may
be used in stopwatch/timer mode)
Procedure:
1. Gather materials
2. Fill one beaker with 300 mL of room temperature water.
3. Take initial temperature.
4. Blow up balloon half-way (keep it small enough to fit easily in beakers) Tie it.
5. Submerge balloon into room temp water for three minutes, then record volume
displacement.
6. Fill other beaker with 300 mL of ice water. (33% ice by volume preferred)
7. Take second temperature of ice water.
8. Submerge balloon into ice water for three minutes, then record volume displacement.
Observation:
1. fill in the table
2. Make a graph of Volume vs Temperature
V1 (initial volume)
V2 (second volume)
T1 (initial
Temperature)
T2 (second
Temperature)
P1 (initial
Pressure)
P2 (final Pressure)
1.2 atm
Unknown
Calculations:
3. If the starting pressure is 1.2 atm – use the combined gas law to calculate P2:
4. If you had put the balloon in water that was 40 C – what would the new Volume be?
5. At 40 C – what would the new Pressure be?
6. a) If the starting temperature was 72 F (room temp), what was it in Celsius? (Hint: C = 5/9(F-32))
___________________________________
b) What was it in Kelvin? (hint: K = 273.15 + C) _______________________________________________
7. Using Gay-Lussac’s Law, if the balloon was at ‘room temp’ and the pressure was 1.5 atm to start with – what
would the pressure be if we had cooled it down to -15 C?
8. Using the combined gas law, if the initial pressure was 1.8 atm in a 1 L balloon at 22.2 C – what was the
pressure if you took away 0.33 L? (Temp remains the same)
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