Internal Energy Theory

Question 1

What is the internal energy of a substance?

Answer 1

The sum of all the individual energies of all the particles in a substance

Question 2

What is a monotamic gas?

Answer 2

A gas where all the molecules are assumed to be point like

Question 3

What are the assumptions made for monotamic gases?

Answer 3

1 - Mass of the molecules is concetrated at a point (meaning no rotational energy)

2 - No chemical bonds between atoms

3 - Internal energy is the sum of translational kinetic energies only

Question 4

What are the key features of a thermodynamic system?

Answer 4

1 - a system: the object or collection of objects that is the focus of attention

2 - a surrounding: everything else in the environment

3 - heat: may be transferred between the system and its surroundings

4 - work: may be done by the system on its surroundings, or vice versa

Question 5

What are walls in the context of thermodynamic systems?

Answer 5

A barrier of some kind which seperates the system from the surroundings

They prevent heat from flowing to the surroundings from the system

Question 6

What are the two types of walls present in a thermodynamic system?

Answer 6

Diathermal: permit heat to flow through them

Adiabatic: perfectly insulating walls (no transfer of heat)

Question 7

What affects the internal energy of a system?

Answer 7

When a system does work (or work is done on a system) there is a change in its internal energy

When a system gains (or looses) heat there is a change in internal energy