Laws Of Thermodynamics

Question 1

Thermodynamics

Zeroth law
First law
Second law
Third law

Answer 1

Thermal equilibrium

Energy in = energy out

Total entropy of an isolated system increases over time in an irreversible system

Every substance has finite positive entropy, but at absolute zero of temp, entropy may become zero

Question 2

Internal energy for isolated sytem

Answer 2

O

Question 3

First law involves work and heat. True or false

Answer 3

True

Question 4

First law involves work and heat. True or false

Answer 4

True

Question 5

Heat expressed as ___ in constant volume

Answer 5

Internal energy

Question 6

Heat expressed as ___ in constant pressure

Answer 6

Enthalpy

Question 7

Recall work equations under different conditions

Free expansion
Against a constant external pressure
Isotherms reversible

Question 8

Total heat content of system

Answer 8

Enthalpy

Question 9

Give pressure and volume dependence of internal energy

Question 10

Give temperature and pressure dependence of enthalpy

Question 11

Give temperature and pressure dependence of enthalpy

Question 12

Recall heat capacity values of ideal gases

Monoatomic
Diatomic/linear polyatomic
Nonlinear polyatomic

Answer 12

Cp
2.5R
3.5R
4R

Cv
1.5R
2.5R
3R

Gamma
5/3
7/5
4/3
Note: Gamma= Cp/Cv

Question 13

Recall heat transactions
Endothermic
Exothermic

Answer 13

∆H>0, surroundings get cooler, system warms
∆H<0, surroundings get warmer, system cools

Question 14

Recall 2 ways of calorimetry.

Coffee cup calorimeter
Bomb calorimeter

Answer 14

Constant pressure, involves small heat changes

Constant volume, involves high amount of heat
and gaseous product

Question 15

Study of heat accompanying chemical changes

Answer 15

Thermochemistry

Question 16

Recall standard enthalpy of formation

Answer 16

Recall standard enthalpy of combustion and it’s special case

Question 17

Shows temp dependence of reaction enthalpy

Answer 17

Kirchoffs law. Recall formula

Question 18

Enthalpy is extensive. Discuss

Question 19

Standard enthalpy of overall reaction is the sum of individual reactions into which the reactions might be subdivided

Answer 19

Hess’ law

Question 20

Phase change occurs at constant ___

Answer 20

Pressure. Thus thermodynamic equation for heat and entropy are for isobaric conditions. Recall formulas

Question 21

Heat accompanying temp change

Answer 21

Sensible heat. Recall formula

Question 22

Heat accompanying phase change

Answer 22

Latent heat. Recall formula

Question 23

∆S (+) denotes ___

Answer 23

More disorder

Question 24

Thermo implications
Impossible for the system oerating cyclically to fully convert heat into work (Kelvin plank)

Answer 24

Impossible for a system operating cyclically and spontaneously to transfer heat from lower to high temp (clausius)

Question 25

In reversible adiabatic expansion heat and entropy is equal to

Answer 25

O

Question 26

Recall carnot cycle. Identify where does heat enters and exits.

Question 27

Converts heat into usable work with release of residual heat

Answer 27

Carnot Heat Engine. Recall efficiency formual

Question 28

Convert work in order to remove a certain amount of heat

Answer 28

Carnot refrigerator. Recall COP

Question 29

Converts work in order to supply certain amint of heat

Answer 29

Carnot heat pump. Recall COP

Question 30

Recall heating curve of water

Answer 30

Region 1: Sensible heat (solid)
Region 2: latent heat (solid and liquid)
….