Properties of Gases The volume of a gas is the same as the volume of its container.
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Properties of Gases The volume of a gas is the same as the volume of its container.
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Transcript of Properties of Gases The volume of a gas is the same as the volume of its container.
Properties of GasesThe volume of a gas is the same
as the volume of its container.
Properties of GasesThe volume of a gas is the same
as the volume of its container.
This is because gases fill the space available.
Measuring gas temperatureTemperature is a measure of the energy of motion of the particles.
Measuring gas temperatureTemperature is a measure of the energy of motion of the particles.
The faster the particles move, the greater the energy and higher the
temperature.
A thermometeris like a speedometer for
molecules.
How fast do gas particles travel?
How fast do gas particles travel?
About 500 meters/second at room temperature.
How fast do gas particles travel?
About 500 meters/second at room temperature.
They collide constantly with each other and the walls of their
container.
The outward push is called pressure.
The outward push is called pressure.
Pressure = Force/Area
The outward push is called pressure.
Pressure = Force/Area
The USA measures pressure as PSI
The outward push is called pressure.
Pressure = Force/Area
The USA measures pressure as PSI (pounds per square inch).
The outward push is called pressure.
Pressure = Force/Area
The USA measures pressure as PSI (pounds per square inch).
The SI measure is kPa (kilopascals).
In an inflated ball,there are more particles inside
than outside.
In an inflated ball,there are more particles inside than outside, so the pressure
inside is greater.
Your chance for fame & fortune!
If you increased the pressure on the outside of the ball, would the
ball change in volume?
If you saidthe ball would get smaller . . .
You could have been famous!
the ball would get smaller . . .If you said
Boyle’s LawWhen the gas pressure increases,
the volume decreases.
When the pressure decreases, the volume increases.
This is called
Boyle’s LawLeast pressure Most pressure
Most volume Least volume
A second chance at fame . . If you put a balloon in the
refrigerator, would it stay the same size, increase in size, or decrease
in size?
And the answer is . . .It would decrease in size?
Charles’s LawWhen the temperature of a gas is increased, its volume increases.
When the temperature decreases, volume decreases.
This is called
Charles’s LawLow temperature High temperature
Low volume High volume
Charles’s LawLow temperature High temperature
Low volume High volume
If you double the temperature, you also double the volume.
Relationship between pressure and temperature.
Low temperature (slow particle movement)
High temperature (fast particle movement)
Low pressure High pressure
Which box below would have the least mass, A or B?
Low temperature
AHigh temperature
B
Low pressure High pressure
The answer is NEITHER. The mass would be the same! WHY?
Low temperature
AHigh temperature
B
Low pressure High pressure
The amount of matter is unchanged.
Low temperature
AHigh temperature
B
Low pressure High pressure
But I’ve always heard that hot air rises, so wouldn’t B be lighter?
Low temperature
AHigh temperature
B
Low pressure High pressure
It would be more accurate to say that less dense air rises.
Low temperature
AHigh temperature
B
Low pressure High pressure
And the density of A and B is the same.
Low temperature
AHigh temperature
B
Low pressure High pressure
So how could you make box B gas less dense than A?
Low temperature
AHigh temperature
B
Low pressure High pressure
When you figure that out, you’ll know the real secret behind why
a hot air balloon floats!
Low temperature High temperature
Low pressure High pressure
