The Math Behind The Gas Laws

The Math Behind The Gas Laws

How Temperature, Volume, Pressure, and Amount Are Related Mathematically

The ABC's of Gas

Multiple Choice

How does the pressure of a container change as the volume is changed?

• As volume increases, pressure increases as well. It is a direct proportion.

• As volume decreases, pressure decreases as well. It is a direct proportion.

• As volume increases, pressure decreases. It is an indirect proportion.

• As volume increases, pressure increases. It is an indirect proportion.

Multiple Choice

Why does a balloon increase its size when you blow into it?

• The balloon expands because you’re adding gas molecules.

• The balloon expands because you’re heating up the air inside.

• The balloon expands because there is no where for the gas already inside to go.

• The balloon expands because you’re lowering the pressure inside

Multiple Choice

If a gas is cooled, how does the volume change?

• The volume of the gas increases.

• The volume of the gas decreases.

• The volume should stay the same.

• The volume will decrease slightly, then increase.

Multiple Choice

Which of the following explains why a hot air balloon inflates when it is heated?

• The increased temperature causes the gases to spread out and inflate the balloon.

• The flame forces more gas particles into the balloon, causing it to inflate.

• The balloon lets the cool air out through the bottom, where it is circulated by the flame.

• The flame lowers the gas pressure inside by heating up the air, causing it to inflate.

Multiple Choice

If you have a 2.0L container of oxygen and a separate 2.0L container of nitrogen at the same temperature, and you compress them both to a volume of 1.0L, what can you expect?

• The oxygen will have a higher pressure than the nitrogen.

• The nitrogen will have a higher pressure than the oxygen.

• The pressure will not change for either container.

• The containers will have the same pressure.

Important Info - KSQ notes'

• Temperature must always be in Kelvins

• Volume should be in Liters; BUT if both the initial volume and final volume have the same unit there isn't a need to convert UNLESS working with the Ideal Gas Law

• Pressure should be in atm (atmospheres) just for our purposes. Just realize that there are other units for pressure

• Look in previous lessons for info to convert temp and volume

• Pressure will always be given in atm.

Boyle's Law - Pressure & Volume

• Indirectly proportional

• According to the graph, the slope of the line... P = k(1/V)

• Rearrange the equation... k - P x V

• Therefore, regardless of the pressure and volume P x V will always = k

• So, P₁V₁ = P₂V₂

• Please watch the video and complete the KSQ notes (Copy the example problem)

• Link to the KSQ Template:

Multiple Choice

Boyle's Law shows the relationship between between which two factors of a gas?

• volume and pressure 
• temperature and pressure 
• pressure and temperature 
• Volume and mass

Multiple Choice

Inversely proportional means as one value increases the other............. 

• increases 
• decreases 
• stays the same 
• goes to zero

Multiple Choice

Which container will have lower pressure?

• left
• right
• they both have the same pressure

Multiple Choice

A sample of hydrogen at 1.5 atm had its pressure decreased to 0.50 atm producing a new volume of 750 mL. What was its original volume?

• 245 ml

• 345 ml

• 123 ml

• 250.mL

Charles' Law - Temperature & Volume

• Directly proportional

• According to the graph, the slope of the line... V = kT

• Rearrange the equation... k = V/T

• Therefore, regardless of the Temperature and Volume, V/T will always = k

• So, V₁/T₁ = V₂/T₂

• Please watch the video and complete the KSQ notes

• Link to the KSQ Template:

Multiple Choice

In Charle's Law, ___________ should always be constant

• Pressure

• Temperature

• Volume

• Mass

Multiple Choice

Records show that the incident of tire explosion is high during summer season.  Which of the following gives the best explanation for this observation?

• there are more travellers during summer vacation
• high temperature during summer season causes the air inside the tire to expand
• vehicles' tires are no well maintained
• there is too much air inside the tires

Multiple Choice

Tom Brady enjoys balloon animals from the carnival. He just received a balloon giraffe that has an initial temperature of 39.0°C and a volume of 1.28 L. If Gronkowski plays a trick on Tom, and puts his balloon giraffe into the freezer, what would be the new volume of the balloon if the temperature drops down to 8.0°C?
(Don’t forget about what must be done to temperatures!)

• 1.42 L
• 6.85 x 10⁴ L
• 3.78 L
• 1.15 L

Multiple Choice

Julian and Jimmy are playing basketball outside in 82°C weather. If they leave the ball outside and temperature drops down to 53°C, what will happen to the volume of the gas in the ball if the pressure remains constant?

• volume will remain the same
• volume will increase
• volume will decrease
• volume will double in size

Guy-Lussac's Law - Temp and Pressure Relationship

• Directly proportional

• According to the graph, the slope of the line... P = kT

• Rearrange the equation... k = P/T

• Therefore, regardless of the Temperature and Pressure, P/T will always = k

• So, P₁/T₁ = P₂/T₂

• Please watch the video and complete the KSQ notes

• Here is the link to the KSQ notes:`

Multiple Choice

• Flask 1 contain the least pressure
• Flask 2 contain the least pressure
• Flask 3 contain the least pressure
• Flask 4 contain the least pressure

Multiple Choice

• Flask 1 contain the most molecules
• Flask 2 contain the most molecules
• Flask 3 contain the most molecules
• Flask 4 contain the most molecules

Multiple Select

Why does increasing the temperature of a gas increase the pressure it exerts?

• It increases the number of particles in the gas.

• It increases the speed of collisions between the particles and the container.

• It increases the size of the particles in the gas.

• It increases the number of collisions between the particles and the container.

Multiple Choice

Increasing the temperature of a gas will _______ the pressure it exerts.

• increase

• decrease

• not affect