Oceans - Entropy

Question 1

what is entropy?

Answer 1

the number of ways that energy can be distributed or arranged

Question 2

what is the symbol for entropy?

Answer 2

S

Question 3

what are the units for entropy?

Answer 3

J K^-1 mol^-1

Question 4

what is entropy dependent on?

Answer 4

state of the molecules involved

no. energy levels

Question 5

how does entropy change depending on physical state?

Answer 5

solids - low entropy

gas - very high entropy

Question 6

why is entropy higher in gases than solids or liquids?

Answer 6

more ways the molecules can be distributed - therefore more ways energy can be distributed

Question 7

how does the no. energy levels in a molecule affect its entropy?

Answer 7

more energy levels = higher entropy

Question 8

if a system is disordered, what will the value of S be?

Answer 8

high

Question 9

if a system is ordered, what will the value of S likely be?

Answer 9

low

Question 10

what is the symbol for the entropy change of a system?

Answer 10

ΔS_sys

Question 11

how is ΔS_sys calculated?

Answer 11

(no. of the product compound present x S of compound) + (no. product compound present x S) … - (no.reactant compound present x S) …..

Question 12

what is the symbol for the total entropy change of a process?

Answer 12

ΔS_TOTAL

Question 13

how is ΔS_TOTAL calculated?

Answer 13

ΔS_TOTAL = ΔS_sys + ΔS_surr

Question 14

what is the symbol for the entropy change of surroundings?

Answer 14

ΔS_surr

Question 15

how is ΔS_surr calculated?

Answer 15

• (ΔH_r / T)

Question 16

if ΔS_TOTAL is positive, what does this tell us about the reaction?

Answer 16

it is possible

Question 17

if ΔS_TOTAL is negative, what does this show about the reaction?

Answer 17

it is impossible

Question 18

if ΔS_TOTAL is 0, what does this show about the reaction?

Answer 18

it is at dynamic equilibrium

Question 19

if ΔS_sys and ΔH_r are positive, when will the reaction occur?

Answer 19

above a given temperature

Question 20

if ΔH_r is positive and ΔS_sys is negative, when will the reaction occur?

Answer 20

never - reaction is impossible

Question 21

if ΔH_r is negative and ΔS_sys is positive, when will the reaction occur?

Answer 21

it will always be possible, no matter the temperature

Question 22

if ΔH_r and ΔS_sys are both negative, when will the reaction occur?

Answer 22

below a given temperature