Gas Practice Quiz

1) Which state of matter is easiest to compress?

• Solid

• Liquid

• Gas

• They are all equally compressible.

Answer explanation

Gas particles are much further away from each other than those in a solid or a liquid. All of this extra space in between them means that it's possible to squeeze a gas much more easily than a solid or a liquid.

2) Why would the gas particles in this container rush out of the opening?

• Gas particles always move from high pressure to low pressure.

• There are more forceful collisions inside the container than outside.

• As the gas particles exit the container, the pressure inside and outside the container begin to equalize.

• All of these are true.

Answer explanation

If the particles inside the container were slamming into the container walls at a higher pressure than the gas outside of the container, as soon as the valve was opened they'd come flying out.

Eventually though, so many particles will leave the container that the gas inside will have the same pressure as the gas outside of the container. If the container is open to the regular outside atmosphere, the pressure it will equalize to is 1 atm

3) Which of the following containers would have the greatest number of gas particle collisions?

• The low pressure container

• The high pressure container

• They have the same number of gas particle collisions

Answer explanation

Pressure is caused by the gas particles slamming into the sides of the container, creating pressure by colliding with them. The more collisions, the higher the pressure.

4) Which of the following are correct units to calculate the temperature and pressure of a gas? (check all that apply)

• deg F & kPa

• K & mmHg

• degree C & atm

• K & atm

• K & kPa

Answer explanation

Kelvin temperature scales never go negative, but Celcius does and that's why we don't use it for gas calculations.

NO SCIENTIST EVER USES FARENHEIT!

atm, mmHg, torr & kPa are all used to calculate gas pressures.

5) What is the temperature in degrees C of a gas at 373 K?

• 273 deg C

• 646 deg C

• -100 deg C

• 100 deg C

Answer explanation

C = 373 - 273 = 100 deg C

6) 2,462.4 mmHg is equal to _____ atm.

Answer explanation

1 atm = 760 atm

Remember to use the steps...

1] Write the given info.

1. 2] Draw a blank conversions factor.

2. 3] Fill in the units.

3. 4] Fill in the numbers. 

     (Which is bigger?  It gets the 1.)

5. 5] Repeat if necessary.