Thermodynamics

Question 1

What is the Kinetic Theory of Matter?

Answer 1

All matter is made of small particles that are in random motion and that have space between them.

Question 2

What is Temperature?

Answer 2

The measure of the average translational kinetic energy of particles.

Question 3

Explain Thermal Equilibrium

Answer 3

Heat is always transferred from a region of high temperature to a region of lower temperature. This process occurs until both regions thermal equilibrium.

Question 4

What is the Zeroth Law of Thermodynamics?

Answer 4

If two thermodynamic systems are in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

Question 5

What is the First Law of Thermodynamics?

Answer 5

Energy cannot be created nor destroyed. 
ΔU = Q + W
ΔU: the change in internal energy (J)
Q: the heat added to the system (J)
W: the work done on the system (J)

Question 6

What is Specific Heat Capacity?

Answer 6

The amount of energy required to increase the temperature of 1kg of a substance by 1°C
Q = mcΔT
Q: the energy transferred (J)
m: the mass of the substance (kg)
c: the specific heat capacity (Jkg^-1 °C^-1)
ΔT: the change in temp (°C)

Question 7

A hot iron bar of mass 2.5kg @ 120°C is placed into a 10kg (10L) container of water @ 20°C. Find the final temperature of the water.

Answer 7

22.6°C. (See Physics Unit 1 Exam Notes for working).

Question 8

What is the formula of Specific Latent Heat Capacity

Answer 8

Q = mL
Q: the energy needed to change state (J)
m: the mass of the substance (kg)
L: the specific latent heat (Jkg^-1)

Question 9

What are the five main postulate of the kinetic molecular thoery?

Answer 9

1 - the particles in a gas are in constant random motion
2 - the combined volume of the particles is negligible
3 - the particles exert no forces on each other
4 - collisions between particles is completely elastic
5 - the average kinetic energy of particles is proportional to temperature in kelvin