thermodynamics

Question 1

specific heat capacity (c)

Answer 1

energy required to increase the temperature of 1kg of a substance by 1k without it changing state

Question 2

amount of energy required to change the temperature of a metal

Answer 2

∆E=mc∆θ

Question 3

specific latent heat (L)

Answer 3

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

Question 4

amount of energy required to change the state of a material

Answer 4

∆E=∆mL

Question 5

types of later heat

Answer 5

fusion=solid to liquid
vaporisation=liquid to gas

Question 6

internal energy

Answer 6

equal to the sum of all the kinetic energies and potential energies of all its particles. these energies are randomly distributed.
when the state of a substance is changed, its internal energy also changes, this is because the potential energy of the system changes, while the kinetic energy of the system is kept constant

Question 7

absolute 0

Answer 7

-273° or 0k, where particles have no kinetic energy and the volume and pressure of gas is 0

Question 8

kinetic theory model

Answer 8

relates several features of a fixed mass of gas, including its pressure, volume and mean kinetic energy.

Question 9

kinetic theory assumptions

Answer 9

-no intermolecular forces act on the particles
-all molecules are the same
-the time taken for a collision is negligible in comparison to the time between collisions
-the motion of molecules are random
-all collisions are elastic
-particles travel in straight lines

Question 11

ideal gases

Answer 11

no interaction other than perfectly elastic collisions between the gas molecules, which shows there are ni intermolecular forces. potential energy is therefore zero as it is related to the intermolecular forces and so the international energy is equal to the sum of kinetic energies of all its particles

Question 12

derivation

Answer 12

do it rn

Question 13

average kinetic energy of molecules

Answer 13

do the derivation rn

Question 14

black body radiators

Answer 14

a perfect emitter and absorber of all EM radiation wavelengths

Question 15

radiation curves

Answer 15

graphs of intensity against wavelength of radiation emitted by objects at different temperatures

Question 16

stephan-boltzmann law

Answer 16

power of blackbody radiator is directly proportional to its surface are and absolute temperature^4

Question 17

wiens law

Answer 17

peak wavelength of emitted radiation is inversely proportional to the absolute temperature of the object.
shows that peak wavelength decreases as temperature increases, meaning the frequency increases so the energy of the wave increases

Question 18

0.5xmx<c^2>

Answer 18

mean kinetic energy of a gas particle

Question 19

3/2xNxKxT

Answer 19

internal energy of the gas, equal to the total kinetic energy of all the particles

Question 20

decrease in volume with constant temp effect on pressure

Answer 20

decrease in volume causes an increase in collisions with the wall. as temp is constant the root mean square does not change. there is an increase in rate of change of momentum as t is smaller and so F is bigger. therefore pressure increases.

Question 21

Boyles law

Answer 21

pressure is inversely proportional to volume

Question 22

Charles law

Answer 22

volume and temperature are proportional

Question 23

pressure law

Answer 23

pressure is proportional to temperature

Question 24

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

Answer 24

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