Thermal Physics and Gases

Question 1

Define internal energy.

Answer 1

The internal energy of an object is the sum of the random distribution of the kinetic and potential energies of its molecules.

Question 2

Define specific heat capacity.

Answer 2

It is the energy needed to raise the temperature of unit mass of the substance by 1 kelvin without changing the state.

Question 3

What is the specific latent heat of fusion of a substance?

Answer 3

The energy needed to change the state of unit mass of a substance from solid to liquid without changing the temperature.

Question 4

State Boyle’s law.

Answer 4

pV = constant (for a fixed mass at constant temperature).

Question 5

State Charles’s law.

Answer 5

V/T = constant (for a fixed mass at constant pressure).

Question 6

State the pressure law.

Answer 6

p/T = constant ( for a fixed mass at with constant volume).

Question 7

What is the ideal gas equation?

Answer 7

PV = nRT

Question 8

What is the Avogadro constant?

Answer 8

It is the number of molecules in 12 grams of carbon-12.

Question 9

State the Boltzmann constant.

Answer 9

R/Na or 1.38 x 10^-23 J K^-1

Question 10

What is the kinetic theory equation?

Answer 10

Internal energy = 1.5nkT =K.E. of n moles of an ideal gas