first law of thermodynamics

Question 1

specific heat capacity

Answer 1

the quantity of heat required to produce a unit temperature rise in a unit mass of the substance without a change in phase of the substance

Question 2

specific latent heat of vaporisation

Answer 2

the quantity of heat required to change unit mass of the substance from the liquid state to its gaseous state without a change in temperature of the substance

Question 3

specific latent heat of fusion

Answer 3

the quantity of heat required to change unit mass of the substance from the solid state to the liquid state without a change in temperature of the substance

Question 4

what assumption is usually made in calculations in this topic

Answer 4

no heat loss to the surroundings

Question 5

internal energy

Answer 5

the sum of a random distribution of potential and kinetic energies of the atoms or molecules in the system

Question 6

an increase in internal energy is due to…

Answer 6

• an increase in the random motion of the atoms or molecules, resulting in an increase in the kinetic energy of the atoms or molecules -> temperature of the body increases
• the separation of the atoms or molecules, resulting in an increase in potential energy

Question 7

first law of thermodynamics

Answer 7

states that the increase in internal energy of a system is the sum of the heat supplied to the system and the work done on the system