thermodynamics

Question 1

what is specific heat capacity

Answer 1

the amount of energy required to change 1kg of a substance by 1k without changing its state

Question 2

what is the equation for energy during a temperature change

Answer 2

∆E=mc∆θ

Question 3

what is specific latent heat

Answer 3

the amount of energy required to change the state of 1kg of a substance without changing its temperature

Question 4

what is the equation for energy during a state change

Answer 4

∆E=ml

Question 5

what is specific latent heat of fusion

Answer 5

energy required in turning a solid to liquid

Question 6

what is specific latent heat of vaporisation

Answer 6

energy required in turning a liquid to gas

Question 7

what is internal energy

Answer 7

the sum of the randomly distributed potential and kinetic energy of all particles in a substance

Question 8

what can cause an increase in total internal energy

Answer 8

a rise in temperature as it increases the average kinetic energy

Question 9

what unit for temperature should be used in thermodynamics

Answer 9

kelvin

Question 10

how to convert Celsius to kelvin

Answer 10

+273

Question 11

what are the kinetic theory assumptions

Answer 11

-the motion of molecules is random
-collisions between molecules are elastic
-time taken during a collision is negligible compared to time between
-molecules move in a straight line at a constant speed
-all particles are identical (same mass and volume)
-intermolecular forces are negligible

Question 12

Boyles law

Answer 12

links pressure to volume, they are inversely proportional

Question 13

Charles’ law

Answer 13

links volume to temperature, they are directly proportional

Question 14

pressure law

Answer 14

links temperature and pressure, directly proportional

Question 15

ideal gas law

Answer 15

combination of Boyles, Charles and the pressure law, linking temperature, volume and pressure
constant=pV/T

Question 16

what is the constant in the ideal gas law

Answer 16

pV=NKT
therefore NK is the constant where k is the Boltzmann constant and N is the number of particles

Question 17

kinetic energy of a gas molecule

Answer 17

1/2 . m <c^2>

Question 18

what is a black body radiator

Answer 18

a perfect emitter and absorber of all possible wavelengths of radiation

Question 19

two laws for black body radiators

Answer 19

wines law and the Stefan-boltzman law

Question 20

if there is a change in temperature and the original pressure is given in a fixed volume, what equation should be used

Answer 20

p1/T1=p2/T2. this is because NK/V is a constant.

Question 21

why does temperature not change during a change in state

Answer 21

the average KE of the molecules is constant. the thermal energy increases the potential energy of the particles which causes the molecules to separate (breaking their molecular bonds)