Gas Laws Homework                                                    Name ___________________

P2V2                                                                   

1.  A balloon is taken from the cold car into the warm house, its volume   increases

     Which gas law does this illustrate? Charles’

                                                       (Boyle’s, Charles’, or Gay-Lussac’s)

2. As the tires on your car cool off over night, the pressure in them goes ________________

     Which gas law does this illustrate? _________________________

 

3.  To use a straw, you use your muscles to increase the size  of your mouth and throat.

      When you do this, the pressure of the air in your mouth  ____________________________

       Which gas law does this illustrate? _________________________

 

4.  A scuba diver holds her breath as she swims to the surface so the

     volume of her lungs ___________________________

     Which gas law does this illustrate? _________________________

5.  What happens to the pressure if molecules of gas are removed from a container? ___________

      (assume that V and T remain constant) would pressure go up or down if there were fewer molecules in the container?

 

6.  What happens to the volume of a gas if the temperature is increased? ____________________

     (assume that P and n remain constant)

 

7.  What happens to the temperature of a gas if the pressure is decreased? ___________________

    (assume that V and n remain constant)

 

8.  What happens to the volume of a gas if the pressure is increased? _______________________

     (assume that n and T remain constant)

 

9.  A balloon of air occupies 2400 ml of space in a room at 22oC.  How big would the balloon be

      in a room that was –36oC? (remember to convert to Kelvins when you are using gas laws)

 

 

 V1  =  V2            solve for V2     

   T1      T2        

 

 

10.  A cylinder of compressed CO2 is used as a propellant in a paintball gun.  The

       cylinder starts out at 20oC with a pressure of 6 atm.  After a few shots, the temperature of the

       gas inside has dropped to –30oC.  What is the pressure? 

Always use Kelvin scale with gas laws

 

 

 

 

       You should have found that the pressure went down.  Why would the pressure drop as the

        gun is fired?

 

      What happens to the number of molecules?

 

11.  A 3500 ml helium balloon is released at sea level where the air pressure is 760 torr.   By the

       time it reaches the top of Mount Everest the pressure only 270 torr.  How big is the balloon at

       this altitude?

 

 

 

 

12.  A SCUBA diver checks her tank’s air pressure on the shore, where the temperature of the

       tank is 25oC, and finds that it has 3200 psi of pressure.  After she paddles out to her dive

       location her tank’s temperature has dropped to 8oC.  What is the new reading on her

       pressure gage? 

First convert temperatures to Kelvins:  25 oC + 273 = 298 K,   8oC+ 273 = 281 K     then use

                                         

 

 

 

13.  A person has a balloon with 1200 ml of air in it, and she is sitting on the runway  in an

       airplane where the temperature was 25oC, and the pressure was 762 torr.  What is the cabin

       pressure when she checks the balloon again at cruising altitude and finds that its volume is

       now 1486 ml and the cabin temp is 15oC?

 

 

 

14.  A SCUBA diver is sitting on the bottom of the ocean at a depth of 40 meters (where the

       pressure is 4.0 atm) when she blows an “air-ring” that has a volume of 184 ml when it leaves

       her mouth.  The temperature of the water (and the air in the bubble) is 4oC.  What is the size

       of the bubble when it is 1 meter from the surface, where the pressure is 1.1 atm and the

       temperature is 30oC?

 

    use the combined gas law

 

 

15.   A 588 ml compressed-air paintball canister is pressurized to 304 atm of pressure at 20oC,

        how many moles of air molecules does it contain?

      Convert 20oC to Kelvins then use

 

16.   If a 25,000 ml  SCUBA tank contains  has 235 moles of air molecules at a temperature of 15 oC, what

       is the pressure?

   

       

 

17.     The diagram below represents an airplane wing.   Circle either   "high" or  "low" to             

         explain how wings provide lift.

Above           Speed:  high or low             Pressure: high or low

     Air flow

 

                             Below           Speed: high or low              Pressure: high or low

 

Answers

9852 ml

732 ml

7.4 moles

595 torr

5 atm

3017 psi

223 atm

1928 ml