Thermodynamics - lecture 1

Question 1

What is an isolated system?

Answer 1

System which exchanges neither energy nor matter

Question 2

Which variables are relevant for an isolated system?

Answer 2

N
V
U

Question 3

What is a closed system?

Answer 3

System which exchanges energy but not matter

Question 4

Which variables are relevant to a closed system?

Answer 4

N
V
T

Question 5

What is an open system?

Answer 5

System which exchanges energy and matter

Question 6

What do the variables N, V , P, U and T mean?

Answer 6

N = Number of moles
V = Volume 
P = Pressure
U = Energy
T = Temperature

Question 7

What is the ideal gas equation?

Answer 7

pV = nRT

Question 8

What is the Van der Waals gas law?

Answer 8

p = nRT / V-nb - a(n/v)²

Question 9

What do a and b stand for in the Van der Waals gas law?

Answer 9

a = attractive interactions 
b = repulsive interactions

Question 10

What are a and b in the Van der Waals gas law?

Answer 10

constants that depend on the particular gas

Question 11

What is the Van der Waals gas law used for?

Answer 11

Non-ideal gases

Question 12

What is work?

Answer 12

The transfer of energy by the application of a force

Question 13

What is the equation for work?

Answer 13

W = - p (Vғ - Vᵢ ) = - pΔV

Question 14

What is the work done ON the gas when compressed?

Answer 14

Positive

Question 15

What is the work done BY the gas when compressed?

Answer 15

Negative

Question 16

Equation relating work done and work by gas?

Answer 16

Work done on the gas = - work done by the gas

Question 17

What is the change in volume for compression?

Answer 17

ΔV < 0

Question 18

What is the change in volume for expansion?

Answer 18

ΔV > 0

Question 19

What is heat?

Answer 19

Transfer of energy down a temperature gradient

Question 20

What is the equation for heat?

Answer 20

q = C (Tғ - Tᵢ) = CΔT

Question 21

What are the units for heat?

Answer 21

q = Joules (J)

Question 22

What are the units for C?

Answer 22

J K⁻¹

Question 23

What is the equation for heat with molar heat capacity?

Answer 23

q = n Cᴍ(Tғ - Tᵢ) = nCᴍΔT

Question 24

What are the units for Cᴍ?

Answer 24

J K⁻¹ mol⁻¹

Question 25

What is the first law of thermodynamics?

Answer 25

Energy is conserved, it can be transferred between place and form

Question 26

What is total energy?

Answer 26

U

Question 27

What is the change in energy for an isolated system?

Answer 27

ΔU = 0

Question 28

What is the change in energy for a closed system?

Answer 28

ΔU = q + w

Question 29

What units are used for the work done equation?

Answer 29

W = joules
P = Pa
V = m3