The Ideal Gas Laws

Question 1

What is the molar form of the ideal gas law?

Answer 1

PV = nRT
Where P is the pressure of the gas, V is the volume taken up by the gas, T is the temperature of the gas, R is the gas constant, and n is the number of moles of the gas.

Question 2

What is a mole?

Answer 2

Moles “n” are a way to describe how many molecules are in a gas.

Question 3

What is the Avogadro’s number?

Answer 3

It is the number of atoms or molecules in one mole of a substance, equal to 6.023E23

Question 4

What are the gas constant ?

Answer 4

R = 8.31 J/ K . mol
R = 0.082 L . atm/ K . mol

Question 5

What units do we plug in for gas constant R= 8.31 J/ K . mol?

Answer 5

• Pressure P in pascal Pa
• Volume V in units of m^3
• Temperature T in units of Kelvin K

Question 6

What units do we plug in for gas constant R= 0.082 L . atm/ K . mol?

Answer 6

• Pressure P in atmospheres (atm)
• Volume V in liters (L)
• Temperature T in Kelvin (K)

Question 7

What is the molecular form of the ideal gas law?

Answer 7

PV = N.kb.T
Where P is the pressure of the gas, V is the volume taken up by the gas, T is the temperature of the gas, N is the number of molecules in the gas, and kb is Boltzmann’s constant

Question 8

What is the Boltzman’s constant?

Answer 8

It is a physical constant that relates the average relative kinetic energy of particles in a gas with the temperature of the gas, which is equal to 1.38E-23 J/K

Question 9

What units do we plug in when using this form of the ideal gas law with Boltzmann’s constant?

Answer 9

• Pressure P in pascal Pa
• Volume V in m^3
• Temperature T in Kelvin

Question 10

What is the proportional form of the ideal gas law?

Answer 10

nR = Nkb = PV/T = constant
This shows that, as long as the number of moles (i.e. molecules) of a gas remains the same, the quantity PV/T is constant for a gas regardless of the process through which the gas is taken.

Question 11

What does the Maxwell-Boltzmann distribution show?

Answer 11

It shows how the speeds of molecules are distributed for an ideal gas.

Question 12

What is the root-mean-square speed?

Answer 12

It is the square root of the mean of the squares of the velocities.

Question 13

What is the total are under the curve on the Maxwell-Boltzmaan distribution?

Answer 13

It represents the total number of molecules in the gas.

Question 14

How does the curve of the Maxwell-Boltzmaan distribution react to the change in temperature?

Answer 14

As the gas gets colder, the graph becomes taller and more narrow. Similarly, as the gas gets hotter the graph becomes shorter and wider.