Thermodynamics Law 1

Question 1

what is Ea expressed as?

Answer 1

change in free energy associated with reaching transition state of rate determining step of reaction

Question 2

delta G has 2 components

what are they?

Answer 2

• enthalpy

- entropy

Question 3

what is enthalpy?

Answer 3

changes in chemical bonding / non - covalent interactions

Question 4

what is entropy?

Answer 4

changes in order/disorder

Question 5

what are the 2 main types of energy?

Answer 5

KE - released in movement

potential energy - energy possessed due to position

Question 6

what is a system?

Answer 6

vessel of interest

Question 7

give eg of systems?

Answer 7

• flasks

- cells/whole animals

Question 8

what is a surrounding?

Answer 8

place where record observations

Question 9

surroundings have ….

Answer 9

constant vol/pressure

remain constant even when system changes

Question 10

what are the 3 system types?

Answer 10

• open: can exchange energy + matter with surroundings
• closed: can exchange energy. NOT matter
• isolated: no exchange

Question 11

heating =

Answer 11

energy transfer between systems + surroundings

Question 12

what are diathermic barriers?

Answer 12

metals, skin, membranes

efficient energy transfer

Question 13

adiabatic barriers prevent …

Answer 13

transfer

Question 14

relief of pressure causes weight to be lifted which is classed as doing …

Answer 14

work

Question 15

sealed systems melt more …

Answer 15

ice

Question 16

if a system does work, w =

Answer 16

negative

Question 17

if a system has work done on it, w =

Answer 17

positive

Question 18

q is negative if system …

Answer 18

heats surroundings

Question 19

a system will do no work if on expansion …

Answer 19

there is no opposing force

Question 20

when does the system do most work?

Answer 20

when opposing pressure is less than internal pressure

Question 21

the temperature of gas is…

Answer 21

same at beginning and end of expansion

Question 22

kinetic energy of perfect gas will remain …

Answer 22

constant

Question 23

the total energy is equal to KE

therefore…

Answer 23

the total energy is constant

Question 24

what is internal energy (U)?

Answer 24

total energy (kinetic + potential) of all atoms, mol + ions that constitute system of interest

Question 25

how is internal energy measured?

Answer 25

looking at changes in work + heat

Question 26

internal energy of the perfect gas is ..

Answer 26

independent of volume it occupies at given temp

Question 27

on a molecular level, the distance between molecules = changing

however what remains the same?

Answer 27

speeds and energies

Question 28

isolated systems have no…

Answer 28

work/heat surroundings

Question 29

internal energies can’t …

Answer 29

change

Question 30

internal energies are …

Answer 30

constant of isolated systems

Question 31

what is the zeroth law of TD?

Answer 31

3 bodies are in thermal equilibrium if no net heat is transferred across boundary

Question 32

what is the 1st law of TD?

Answer 32

internal energy of isolated systems = CONSTANT