Gases Test Flashcards
5 main points of the molecular theory
- the gas consists of objects with a defined mass and zero volume
- the gas particles travel randomly in a straight line motion where their movement can be described by the fundamental laws of mechanics
- all collisions involving gas particles are elastic; the KE pf the system is conserved even though the KE among the particles is redistributed
- the gas particles do not interact with each other or with the walls of any container
- the gas phase system will have an average KE that is proportional to temperature; the KE will be distributed among the particles according to a Boltzmann type of distribution
What is Boyle’s Law?
Boyle’s law states that the pressure on a gas is inversely proportional to its volume, when all other variables are controlled.
What is the formula for Boyle’s law?
P1xV1= P2xV2
What did Robert Boyle invent?
the air pump
How can the KMT be used to explain Boyle’s law?
the KMT can be used to explain Boyle’s law because gases are composed of particles travelling in straight line motion that are separated from each other. Therefore, when pressure is applied to a trapped gas, the space and volume available for gas to travel decreases
Describe and explain method used by Boyle:
conduct experiment- organize data into chart- graph data- regraph if necessary- make equation
How does a Cartesian diver work?
- When pressure is exerted on the air at the top, the air exerts that same pressure on the liquid below it.
- The liquid cannot compress, and thus exerts that same pressure on every surface within it. The liquid exerts that pressure up into the Cartesian diver and on the air pocket inside the diver.
- From Boyle’s law we know that as pressure increases, the volume decreases
- As pressure increases on the air pockets, the volume of the air pocket decreases the liquid pushed into the diver.
- This causes the weight of the diver to increase, whilst its volume stays constant, thus the density of the diver increases.
- As its density increases, it SINKS
- When the air pressure on the top is released the air pocket expands and the diver rises.
What is Charles Law?
Charles law states that the volume of a gas is directly proportional to the temperature in kelvins
What is the formula for Charles law?
V1/T1=V2/T2
What was produced as a result of CharlesLaw?
the hot air balloon
How can KMT be used to explain why an increase in temperature will result in an increase in volume, provided type, amount, and pressure of the gas remains constant?
The KMT says that the avg. KE of the particles is directly proportional to its kelvins temperature. Thus as temperature increases, the velocity of the particles increases. These particles would then hit the sides of the container harder, exerting more pressure. If the pressure were to remain constant, the volume would have to increase. This ensures more time between collisions as the gas particles bounce from side to side.
What is absolute zero?
The temperature at which the avg. KE of a gas is zero. Its the lowest temperature that can exist. Its 0K or -273.15 degrees Celsius
Why are Kelvins used in Charles law?
Because if Kelvins are used then the volume versus temperature graph will have no y intercept, and thus no’b’ in the y=mx+b template. And the degree Celsius unit leads people to believe in the false notion that temperature can continue to get ‘colder’. And with kelvins, once you drop to zero, you can’t go any lower.
How come when someone holds one of the 2 bulbs with gas, the gas then bubbles out into the other bulb. Use at least 3 logical steps in your explanation.
- When someone holds one of the bulbs with gas, that region will experience a temperature increase
- From Charles law we know that if temperature increases so must the volume in equal proportion.
- Thus the gas in region A must expand and bubble over to the other bulb.
Gay lusssacs law
states that the pressure of a gas is directly proportional to temperature if all other variables are held constant.
