Chapter 14 Thermal Physics

Question 1

what is the triple point of a substance

Answer 1

one specific temperature and pressure where the substance exists in thermal equilibrium and all three phases of matter

Question 2

what is the zeroeth law of thermodynamics

Answer 2

if two objects are in thermal equilibrium with a third then all three are in thermal equilibrium with each other

Question 3

what is the absolute temperature scale

Answer 3

temperature scale that uses the triple point of pure water and absolute zero as its fixed points

Question 4

what is the base SI unit for the absolute temperature scale

Answer 4

Kelvin K

Question 5

how do you convert from Kelvin to celsius and vice versa

Answer 5

Kelvin –> Celsius
-273
Celsius –> Kelvin
+273

Question 6

what is the value of absolute zero in both K and C

Answer 6

0K

-273C

Question 7

what is the kinetic model

Answer 7

a scientific model that demonstrates the arrangement of atoms or molecules for the different phases of matter for a substance

Question 8

describe the kinetic model of a solid and its properties

Answer 8

atoms are tightly packed in a regular structure
strong electrostatic forces of attraction
atoms vibrate

Question 9

describe the kinetic model of a liquid and its properties

Answer 9

atoms are close together and fill container

can change position and flow past each other

Question 10

describe the kinetic model of a gas and its properties

Answer 10

atoms are very far apart

atoms can move freely in random directions at different speeds

Question 11

how does kinetic energy of the particles change from solid to gas

Answer 11

the kinetic energy of the particles increase

Question 12

how does potential energy stored in bonds change from solid to gas

Answer 12

the potential energy stored in the bonds increases from solid to gas

Question 13

what was the brownian motion experiment

Answer 13

in 1827 Robert Brown looked through a microscope and observed the random movements of fine pollen grains floating on water

Question 14

what does the spacing between particles affect

Answer 14

density of the substance

Question 15

what is the internal energy of a substance

Answer 15

sum of randomly distributed kinetic and potential energies of atoms or molecules

Question 16

what two things can increase the internal energy of a substance and how

Answer 16

> temperature increase the KE of a particle because they move faster
when a substance changes phase potential energy increases because the IMF decrease

Question 17

what is specific heat capacity

Answer 17

energy required per unit mass to change the temperature by 1K

Question 18

what is the specific heat capacity equation

Answer 18

E = m c Δθ
Energy = mass x SHC x change in temp

Question 19

describe the experiment to determine the SHC of a solid

Answer 19

place block in insulation with hole for heater and thermometer
insert heater and attach to power supply
record the power supplied, initial and final temp, mass of block and time power supplied

Question 20

describe the experiment to determine the SHC of a liquid

Answer 20

place beaker of liquid in insulated container and cover with lid and place a thermometer in
hookup power supply for heater
record power supplied, change in temp, mass of liquid, time power supplied

Question 21

what is the first step for method of mixtures

Answer 21

write down all the values you know and use the E = mcθ equation

Question 22

what is the method of mixture equation

Answer 22

E1 = E2
m1c1θ1 = m2c2θ2

Question 23

what are the second and third steps for method of mixture

Answer 23

rearrange the method of mixtures equation to find the value you need and then calculate

Question 24

what is specific latent heat

Answer 24

the amount of energy required to change the phase per unit mass while at constant temperature

Question 25

what is the specific latent heat equation

Answer 25

E = m L

Question 26

what is the specific latent heat of fusion

Answer 26

the energy required to melt 1 kg of a solid into its liquid form

Question 27

what is the specific latent heat of vaporisation

Answer 27

energy required to boil 1 kg of a liquid into is gaseous form