# data[].attributes.body
Entropy : Is the measure of disorder in a system.

ΔS  =ΔS(products)-ΔS(reactants)

Harder substances have lower entropy.

The more complex substances will have a more entropy.

Gibbs Free energy (ΔG) is the available energy of a substance that can be used in a chemical reaction.
ΔG = ΔH - TΔS

Q=IT

Spontaneous :
ΔG is (-)
ΔH is (+)
ΔS is (-)

Non- spontaneous:
ΔG is (+)
ΔH is (-)
ΔS is (-)

Electrolysis: is the decomposition of compound into its elements by passing an electric current.

Oxidation occurs in anode

Reduction occurs in cathode

# data[].attributes.body
Entropy (S) is the measure of disorder in a system.
ΔS (system) = S (final) - S (initial)

More complex substances have more entropy.

Harder substances have lower entropy.

Gas generally has higher entropy.

Gibbs Free energy (ΔG) is the available energy of a substance that can be used in a chemical reaction.

ΔG = ΔH - TΔS(system)

If enthalpy and entropy values are both positive, the reaction is non-spontaneous. Will be spontaneous if the value of T is large enough.

If enthalpy and entropy values are both negative, the reaction is non-spontaneous. Will be spontaneous if the value of T is low enough.

When enthalpy is negative and entropy is positive, and vice versa, the reaction will be spontaneous.

Electrolysis is the decomposition of compound into its elements by passing an electric current.

Oxidation occurs at the anode. Reduction occurs at the cathode.

# data[].attributes.body
* ΔG = ΔH - TΔS (Temperature has to be Kelvin).
* ΔH (+) , ΔS (+), it is spontaneous, T ↑
* ΔH (+) , ΔS (-) , it is non spontaneous.
* ΔH (-) ,  ΔS (+), it is spontaneous.
* ΔH (-) ,  ΔS (-) , it is spontaneous, T ↓

*Electrolysis is a decomposition of a compound
into its elements by an electric current.
*Electrolyte: The compound that is decomposed
(molten/aqueous).
*Electrodes: Carbon/Metal
*Anode - anions
*Cathode - Cations
*Power supply must be direct current.
*Cations move to cathode and gain electrons
(Reduction).
*Anions move to Anode and loses electrons
(Oxidation).

# data[].attributes.body
Entropy - measure of randomness or disorder of system
- measure of dispersal of energy at a specific temperature
- exothermic

entropy of gas > liquid > solid
complex > simple

temperature increase, entropy increase

ΔS system = ΔS products - ΔS reactants

Gibbs Free Energy
ΔG = ΔH reaction - TΔS system

spontaneous (feasible) :
ΔG negative
ΔH negative
ΔS positive

non spontaneous (not feasible) :
ΔG positive
ΔH negative
ΔS negative

Electrolysis
anode : positive electrode
cathode : negative electrode

1F = 96500 charge

Q = It

# data[].attributes.body
i learnt that:

gibs free energy tells us whether something is spontaneous or not

must be negative for the reaction to be spontaneous

if enthalpy is positive and entropy is negative, reaction is not spontaneous

if enthalpy is negative and entropy is positive, reaction is spontaneous

if enthalpy is positive and entropy is positive reaction is spontaneous under high temperature

if enthalpy is negative and entropy is negative, reaction is spontaneous under low temperature

equation: G= H - TS

Electrolysis

decomposition of a compound into its elements by electric current

redox reactions in electrolysis

faraday is the quantity of electric charge carrier by 1 mole of electrons

1 faraday is 96500 charge

equation: Q= I x T

things i need to focus more:

i have to focus more on the calculation part because it kind of still confuses me

comments on teachings:

i learnt a lot of things and mr gopi was very detailed in teaching

# data[].attributes.body
Entropy and Gibbs Free Energy

1. Entropy is a measure of disturbance in the system

2. ΔS of system = ΔS of product - ΔS of reactant

3. ΔG = ΔH - TΔS (T is in Kelvin)

4. When Gibbs free energy is negative, the reaction is spontaneous

5. ΔH (+) , ΔS (+) , T is high , spontaneous

6. ΔH (-) , ΔS (-) , T is low , spontaneous

7. ΔH (+) , ΔS (-) , non spontaneous

8. ΔH (-) , ΔS (+) , spontaneous

Electrolysis

1. Cathode is negative electrode, anode is positive electrode

2. Reduction in cathode, oxidation in anode

3. 1 Faraday = 96 500 Coulombs

4. 1 Faraday is the charge carried by one mole of electron or one mole of singly charged ion

5. Mass of substance deposited depends on the strength of electric current and time

6. Q=It

# data[].attributes.body
Spontaneous reaction :
- Gibbs Free Energy must be negative
- Enthalpy is negative (-) & Entropy is positive (+)
- Enthalpy & Entropy is both negative (-) at lower temperature
- Enthalpy & Entropy are both positive (+) at higher temperature

Non-spontaneous :
- Enthalpy is positive (+) & Entropy is negative (-)

Entropy change = Entropy Products - Entropy Reactants

Higher entropy :
- More disorder
- More number of atoms

1Faraday = 96 500Charge carried by 1 mol of electrons to form 1 mol of ion

Teaching: It was good

# data[].attributes.body
Entropy
- Entropy value in gas > liquid > solid
- Substances with fewer atoms = lower entropy
- Harder substances = lower entropy
- Delta S system = Delta S products - reactants

Gibbs Free Energy
- Delta G = Delta H - T*Delta S system
- (-) gibbs free energy = spontaneous
- (+) entropy & (+) enthalpy = spontaneous at high temp
- (-) entropy & (-) enthalpy = spontaneous at low temp
- (+) entropy & (-) enthalpy = spontaneous
-(-) entropy & (+) enthalpy = non-spontaneous

Electrolysis
- decomposition of compound into its elements by electric current
- Q = IT
- 1 F = 96 500C

I also learned how to calculate the amount of products produced after electrolysis from this new knowledge which I still have to do more practice.

# data[].attributes.body
Today i learned more on gibbs free energy.     ΔG= ΔH - TΔS

I also learned some ways to easily remember how temperature is affected by the entehopy and enthalpy change being positive and negative.

And abit of electrolysis using faraday as a measure to calculate moles within an equation.

# data[].attributes.body
- revision on gibbs free energy and the formula

-its relationship to entropy and enthalpy

-spontaneity calculation

Electro chemistry

Revision on basics of hydrolysis

# data[].attributes.body
In today's lecture we revised about
-entropy and its definitions
-factors that affect entropy
-entropy change in a system
-formula for gibbs free energy
-use of quadrants
-and Faraday

# data[].attributes.body
Entropy is the measure of disorder of a system. If entropy increases, it becomes more disordered. To find change in entropy we use the formula S products - S reactants.

We also learnt about Gibbs Free energy, given by the formula:
Change in Gibbs Free energy = Enthalpy Change - Temperature x Entropy Change.

# data[].attributes.body
- Entropy refers to the measure of disorder in a system.

- Gibs free energy = Enthalpy - (Temperature)(Entropy)

- If Gibs free energy is (-) then reaction is spontaneous at 298 Kelvin

- If Gibs free energy is (+) then reaction is non-spontaneous at 298 Kelvin

- Review about how we can tell if it is spontaneous from negative and positive enthalpy and entropy

- 1 Faraday = 96500 C (Electrolysis)

# data[].attributes.body
ENTROPY

1. entropy : measure of number of possible arrangements of the particles and their energies (measure of disorder of the system)

2. gases has higher entropy compared to solids and liquids

3. simpler substances with fewer atoms have lower entropy values compared to more complex substances with more no. of atoms

4. harder substances have a lower entropy value (diamond has a lower entropy compared to graphite)

5. the more the gas molecules, greater no. of ways to arrange them and higher entropy (ordered to disordered) : endothermic

6. decrease in entropy if, disordered to ordered : exothermic

7. entropy of system : entropy of products — entropy of reactants

GIBBS FREE ENERGY CHANGE

1. Gibbs Free Energy = enthalpy change — (temperature)(change in entropy)

2. if negative value —> feasible/spontaneous at 298 K

3. if positive value —> not feasible/not spontaneous at 298 K

Enthalpy change = positive, entropy = positive, only spontaneous when temperature is higher
Enthalpy change = negative, entropy = negative, only spontaneous when temperature is lower
Enthalpy change = negative, entropy = positive, spontaneous
Enthalpy change = positive, entropy = negative, non-spontaneous

ELECTROLYSIS

1. cations move to cathode and gains electrons (reduction)

2. anions move to anode and lose electrons (oxidation)

3. OIL RIG

4. the mass of substance produced at electrode is proportional to time and strength of the electric current

5. Q = It

6. faraday is the quantity of electric charge carried by 1 mole of electrons or 1 mole of singly charges ions

# data[].attributes.body
From today's lecture, we learnt about entropy, Gibbs free energy and electrolysis. Below you can find the important things learnt from the lecture.

Entropy (S)

Measure of disorder of the system and dispersal of energy in a system

Factors affecting Entropy

State of Particle

Temperature

Number of Atoms

Structure of Atoms

ΔS system = S products - S reactants

Gibbs Free Energy (ΔG)

ΔG= ΔH - TΔS system

Enthalpy(+) , Entropy(-) (non-spontaneous)

Enthalpy(-) , Entropy(+) (spontaneous)

Enthalpy(+) , Entropy(+) (temperature must be higher for a spontaneous reaction, as ΔG depends on T, if T increases, value of (-TΔS) is more negative, so ΔG is more negative, hence its more  spontaneous)

Enthalpy(-) , Entropy(-) ( temperature must be lower for a spontaneous reaction, as ΔG depends on T, if T decreases, value of (-TΔS) is less positive, so ΔG is more negative,  hence its more  spontaneous)

Electrolysis

decomposition of a compound into its elements by an electric current

anode (positive electrode, anions, oxidation)

cathode (negative electrode, cations, reduction)

electrolyte (molten/concentrated aq.) and electrode (carbon/metal)

Quantitative Electrolysis

Q = I x t

Faraday

quantity of electric charge carried by 1 mole of electrons or 1 mole of singly charged ions

1 F = 96500 C

After today's lecture, I feel like I need to give more attention to spontaneous and non-spontaneous reactions. Other than that — today's lecture was good and easy to understand.

# data[].attributes.body
Entropy is the measure of disorder of a system

Gases hv the highest entropy, and we can use this to predict the sign of the change in entropy of a reaction

G=change in enthalpy - Temp x change in entropy

If G >0, reaction non- spontaneous
If G < 0, reaction spontaneous
Electrolysis:

Cathode- cation,
Anode-anion

Hi sir Gopi! Thanks for the very nice lecture, you explained the concepts very well and allowed me to understand better

# data[].attributes.body
Entropy:
-Measure of disorder of the system
-Gases>Liquid>Solid
-Entropy of system = Entropy of product - Entropy of reactants
-The more gas molecules formed in a reaction, the higher the entropy.
-If Gibbs free energy = Positive, reaction is spontaneous.
-G = H - TΔS
-Temperature must be in Kelvin (298K)

# data[].attributes.body
-ΔG = Spontaneous & non feasible

Gibbs Free energy:
ΔG= ΔH - TΔS

Faraday:
96500C in 1 mol of electron

# data[].attributes.body
I learned about entropy, gibbs free energy, and electrolysis

ENTROPY

Measure of number of possible arrangements of the particles and their energies or disorder of the system

Delta S system = Delta S products - reactants

GIBBS FREE ENERGY

Delta G = Delta H - T Delta S

When entropy +  and enthalpy - the reaction is spontaneous

When entropy - and enthalpy + the reaction is non-spontaneous

When entropy + and enthalpy + the reaction is spontaneous if T is high

When entropy - and enthalpy - the reaction is spontaneous if T is low

ELECTROLYSIS

Decomposition if a compound into its elements by an electric current

Anode: positive electrode, anions, oxidation

Cathode: negative electrode, cations, reduction

Quantitative electrolysis (Q = It)

Faraday (the quantity of electric charge carried by 1 mole of electrons or 1 mole of singly charged ions, 1F = 96500 C)

# data[].attributes.body
Entropy is the measure of disorder and randomness in a system. If entropy(ΔH) is negative and enthalpy(ΔS) is positive, it would be a non spontaneous reaction. If entropy is positive and enthalpy is negative, it would be a spontaneous reaction. If both entropy and enthalpy is positive, reaction will only be spontaneous at high temperature. If both entropy and enthalpy is negative, reaction will only be spontaneous at low temperature.

# data[].attributes.body
We revised on:
Entropy is the measure of disorder and dispersal of energy in a system.
The more random it is, the higher the entropy.
Gas>Liquid>Solid.
The more atoms there are, the higher the entropy
CO2 > CO

Entoropy (-), Enthalpy (+) --> NON SPONTANEOUS
Entropy (+), Enthalpy (-) --> SPONTANEOUS

Gibbs Free Energy:
Enthalpy - (T) x Entropy
G = H - TS
(Gopi is not so hot si)
Standard condition -> 298K

Electrolysis: Decomposition of ionic compound to its ions by electric current

Faraday: the electric charge carried by one mole of electron form one mole of an ion.
1F : 96500 coloumbs (1 mol of electron)

# data[].attributes.body
During the lecture, I have learnt about Gibbs Free Energy . I learnt how to calculate it ,as well as predict its feasibility in various reactions.

I also learnt about electrolysis. I learnt that the mass of substance produced is propotional to time and current. (Q = IT). Then, I learnt about faraday (1F = 96500 C). It is the quantity of electric charge carried by 1 mole of electrons or 1 mole of singly charged ions. Lastly, I learnt how to apply these in various calculations.

# data[].attributes.body
Reviewed about
- entropy (definition)
- entropy relationship with temp, number of mol, state of matter, hard/soft material
- Formula for entropy
- Gibbs free energy
- formula
- must use 298 for calculation
- spontaneous or not (diff sign of enthalpy and entropy)

Learned about
- Electrolysis(definition)
- anode/cathode
- Faraday (1F=96500C)

# data[].attributes.body
I have learnt the following ideas:

1. Reviewed the definition of entropy.

2. Reactions are spontaneous when delta G is negative, non-spontaneous when delta G is positive, at that given temperature.

3. Gibbs Free Energy = Enthalpy change of reaction -T(delta S)

4. Reviewed the use of quadrants.

5. When delta H (+) and delta S (-), the reaction is not spontaneous.

6. When delta H (-) and delta S (+), the reaction is spontaneous.

7. When both delta H and delta S are negative, the reaction is spontaneous at low temperatures. Else, when both are positive it is spontaneous at high temperatures.

8. Learnt about the background knowledge of electrochemistry.

9. One Faraday is the charge carried by one mole of electrons or singly-charged ions.

10. 1 F = 96500 C

11. To solve the questions, first equate and find the number of electrons involved.

12. Ensure that all reactions are calculated using the same units. Entropy is usually measured in J/Kmol and not kJ/Kmol. The quantity t in (Q = It) is measured in seconds.

# data[].attributes.body
What I learn:

definition of entropy and what affects it

how to calculate Gibbs Free energy and its trends

if Gibbs Free is positive is is non spontaneous, but if it is negative it is spontaneous

definition of electrolysis and its components

faraday: 96500 Coulombs

the lesson was clear but the part on electrolysis is a bit fast

# data[].attributes.body
Best chemistry teacher ever

# data[].attributes.body
I learn about the meaning of entropy, and about spontaneous and non-spontaneous reaction. Spontaneous reaction occur when both entropy and enthalpy positive in high temperature or when the entropy is positive and enthalpy is negative , while non-spontaneous reaction occurs when entropy is negative and enthalpy is positive or when both is negative in low temperature. Gibbs free energy is the enthalpy change minus the product of temperature and entropy change. Electrolysis is the decomposition of ionic compounds with the use of electric current. Faraday is the quantity of electric charge carried by 1 mole of electrons or 1 mole of charged ions.

# data[].attributes.body
Entropy is the measure of disorder and dispersal of energy in a system
factors:
#amount of atoms
#change in state
#order and compact
-Formula of gibbs energy:
gibbs=enthalphy-(T)entropy
-electrolysis is the decomposition of ionic compounds with the use of electric current
#electrolyte, compound that is decomposed in molten state
#electrodes, carbon or metal
#anode,positive electrode
#cathode,negative electrode

Faraday is quantity of electric charge carried by 1 mole of electrons or 1 mole of charged ions

Ag+ e- -> Ag (e- 1F)

1 F if electricity 96 485 CC/96 500CC

# data[].attributes.body
gibs free energy = enthalpy -temperature x enthalpy

spontaneous if (-)

entropy depends on temperature, state, size of molecule and hardness which can be measured with the equation
enthalpy of product - enthalpy of reactants

electrolysis requires  molten of aq electrolyte

Faraday is 96500 C carried by one mol of electrons

# data[].attributes.body
Revision

Entropy: Measure of disorder and randomness in a system.

Entropy calculated is:
Entropy of system = entropy of product = entropy of reactants

Gibbs Free Energy: Used whether or not a reaction is feasible/spontaneous.
Gibbs Free Energy can be calculated with :
G = H - TΔS
Temperature is usually calculated under standard conditions (298K)

A reaction can be easily decided wether it is spontaneous or not by using the signs.

Electrolysis: Decomposition of ionic componds to its ions using an electric current.
Learnt about Faraday.
Faraday: the electric charge carried by one mole of electrons form one mole of an ion

-Lesson was good and easy to understand

# data[].attributes.body
if both enthalpy change and entropy change are positive then high temperature is needed for the reaction to be spontaneous, lower temperature is needed if both entropy and enthalpy change are negative. Harder substance, complex subtance have higher entropy value. Entropy value is proportional to the temperature. Gas molecules have higher entropy > liquid > solid.
Electrolysis is a process of decomposing compound by an electric current. Anions are attracted to anode, Cations are attracted to cathode

# data[].attributes.body
- entropy (-), enthalpy (+) would be a non spontaneous reaction
- if both entropy and enthalpy is (+), temperature must be higher for spontaneous reaction
- entropy (+), enthalpy (-), would be a spontaneous reaction
- if both entropy and enthalpy is (-), temperature must be lower for spontaneous reaction

- i need to focus more on the spontaneous and non spontaneous reactions, and also electrolysis

- teaching was good, but the electrolysis part was a bit fast

# data[].attributes.body
Gibbs free energy is the enthalpy change minus temperature times entropy change. Temperature must be in kelvin. Gibbs free energy must be negative in order to say that the reaction is feasible. Entropy of the system is equal to entropy of the product minus entropy of the reactant. If Gibbs free energy is positive, reaction is not spontaneous. Prediction of feasibility of reaction: If enthalpy is negative and entropy is positive, reaction is spontaneous. If enthalpy is positive and entropy is negative, reaction is non spontaneous. Electrolysis is the decomposition of a compound into elements by an electric current. Anions like to go to anode. Cathode attracts cations. Quantitative electrolysis: the mass of substance produced at electrode depends on the time and the strength of the electric current. Q=It Time must be in seconds. Faraday is the quantity of electric charge carried by 1 mole of electron. 1F equal to 96500C.

# data[].attributes.body
Learnt about:

Entropy: Measure of disorder in a system
Trends of entropy

How to calculate Gibbs free energy change
Trends of Gibbs free energy

Electrolysis: Decomposition of ionic compound to its ions by electric current.

Faraday: 96500 Coulombs (1 mole of electrons)

# data[].attributes.body
Entropy is the measure of disorder and randomness in a system.
Entropy of system = entropy of product = entropy of reactants
Gibbs Free Energy is used to find out whether or not a reaction is feasible/spontaneous.
G = H - TΔS
(Gopi is not so Hot Si)
Temperature is usually calculated under standard conditions (298K) (25C)
A reaction can be easily decided whether it is spontaneous or not by using the signs.

if entropy (-), enthalpy (+) it will be a non spontaneous reaction

if both entropy and enthalpy is (+), temperature must be higher for a spontaneous reaction

if entropy (+), enthalpy (-), it will be a spontaneous reaction

if both entropy and enthalpy is (-), temperature must be lower for spontaneous reaction

Electrolysis is the decomposition of ionic compounds to its ions using an electric current.
Faraday is the electric charge carried by one mole of electrons form one mole of an ion
The lesson was good and easy to follow. It was also not boring.

# data[].attributes.body
Entropy Revision and Gibbs Free Energy

entropy: measure of number of possible arrangements of the particles and their energies (measure of disorder of the system)

gases > liquid > solid

simpler atoms with fewer atoms have lower value (e.g. CO2 > CO; CO2 has more forms of arrangements)

harder substances have a lower entropy value (e.g. diamond and graphite - allotropes; diamond harder -> rigid, not moving around -> entropy lower // graphite softer, sliding)

temperature increase -> more disorder, increase in entropy

reactions

more gas molecules, greater number of ways to arrange them and higher entropy

decrease if disordered -> ordered (e.g. N2(g) + 3H2(g) -> 2NH3(g))

ENTROPY OF SYSTEM = PRODUCT - REACTANTS

Gibbs Free Energy Change

enthalpy change - temperature x entropy change

gibbs free energy positive -> not spontaneous

- H, + S -> spontaneous // +H, -S -> not spontaneous

same signs -> solid - liquid e.g. ice to water, +H, +S, spontaneous above 0°C

entropy enthalpy

+ - spontaneous, -+ non-spontaneous, ++ spontaneous at high temp, -- spontaneous at lower temp

Electrolysis

decompostion of a compound into its elements by an electric current

electrolyte: compound that is decomposed (molten/concentrated aq)

electrodes: carbon/metal

anode: positive electrode

cathode: negative electrode

redox:

cations to cathode and gains electrons (reduction, e.g. Zn2+ + 2e- -> Zn)

anions to anode and lose electrons (oxidation, e.g.  2Cl- -> Cl2 + 2e-)

overall reaction -> ZnCl2 -> Zn + Cl2

Quantitative Electrolysis

mass of substance produced at electrode deends on:

time

electric current

(Q=It)

Faraday

quantity of electric charge carried by 1 mole of electrons or 1 mole of singly charged ions

Ag+ + e- -> Ag (e- 1F)

1 F if electricity 96 485 CC/96 500CC

# data[].attributes.body
- Entropy : Measure of disorder of the system
- Compare entropy value :
* Gases - Higher entropy
* Solid - Lower entropy
* Greater number of atoms - Higher
* Diamond : Hard - Rigid ordered - lower entropy
* Graphite : Less rigid - less ordered -Greater entropy

-The more gas molecules : entropy will be greater
* (s) -> (s) + (g) : ordered - disordered - +
* (g) -> (g) + (g)

- Entropy change system = Entropy change product - Entropy change reactant

Gibbs Free Energy change
- S = + (ordered -> disordered)
- Feasible & spontanious
- Enthalpy change G = H - T(change in entrophy in system)
* T = kelvin (K) - 298K (standard condition)
- Gibbs Free : Negative (reaction is feasible / spontanious)
- Include temp

Will effect/influence
- Enthalphy and Entrophy :
* Enthalphy : + , Entrophy : -, (non spontaneous)
* Enthalphy : - , Enthrophy : +, (spontaneous)
* Enthalphy : - , Enthrophy : - , T : spontaneous Lower
* Enthalphy : +, Enthrophy : +, T : spontaneous Higher

Electolysis
- Decomposition by electric current
- Electrolyte : molten/ conc.aq
- Electrodes : Carbon/Metal
- Anode <- Anions , Oxidation
- Cathode <- Cations, Reduction
- Aq have :
* H+ , OH-
- If they are not molten , ions cannot move
- Quantitative electrolysis
* The mass of substance produced at electrode is proportional to :
1. Time
2. Strength of the electric charge
Q =IT
- Faraday : quantity of electric charge carried by 1 mole of electrons or 1 mol of singly charged ions (96 500C)