Topic 3

Question 1

Assumptions of the ideal gas model

Answer 1

-There are no forces between the particles
-the molecules obey Newton’s laws
-all collisions are perfectly elastic

Question 2

Specific latent heat of fusion

Answer 2

The energy needed to change 1kg of a solid into a liquid with no change in temperature

Question 3

Specific heat capacity

Answer 3

The energy needed to raise the temperature of 1Kg of a substance by 1 kelvin

Question 4

When can you apply the deal gas equations to real gasses?

Answer 4

At low pressures and densities; moderate to high temperatures

Question 5

Mole

Answer 5

The quantity containing as many elementary units as there are atoms in 0.012

Question 6

Temperature of a substance represent

Answer 6

Temperature (in kelvin) is directly proportional to to the average kinetic energy of the molecules

Question 7

Difference between internal energy and thermal energy

Answer 7

Internal energy is the total kinetic energy and potential energy of molecules of a body; thermal energy is a (net) amount of energy transferred between two bodies at different temperature

Question 8

Difference between evaporation and boiling

Answer 8

Evaporation takes place at any temperature and involves a reduction in temperature, over the surface of a liquid. Boiling takes place at constant temperature in the whole volume of the liquid

Question 9

Internal energy

Answer 9

Sum of kinetic energy and intermolecular potential energy of the molecules in a substance