REFLECTION ON LECTURE 10 ELECTRODE POTENTIAL by Pooganeswari Siteram Pillai https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr Please write the important things that you have learned today, the areas that you need to revise more, and comment on my teachings. en-us 2021-09-15 16:21:19 UTC 2021-09-20 06:15:17 UTC hello@padlet.com Davis JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1744718224 During this lecture i learnt about electrode potential. I learnt that for potential difference, the equation must be in reduction form. The one that is more positive goes to the right and the more negative goes to the left. 
The V is always the same even when halfed. (Cl2 and 1/2Cl2)

To calculate the voltage generated, reverse the more negative equation and change the voltage to positive (if negative) or vice versa.
Then add up the voltage. 

I also learnt about salt bridge , which is the movement of ions between two half cells. (Prepare with potassium/sodium nitrate, so it wont form any precipitate)

Finally, i learnt further about the 3 types of half cells.
Metal/Metal ion (Zn/Zn2+)
Non metal/non metal ion (Cl2/Cl-)
Ion/ion (Fe3+/Fe2+)]]> 2021-09-16 03:22:56 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1744718224 Kenneth MS https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1744744160 I learnt about electrode potential, salt bridge

The equation of potential difference is always in reduction form. The E value of any equation is the same even if the products are multiplied.

Salt bridge is the movement of ions between 2 fall cells. 


]]> 2021-09-16 03:34:12 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1744744160 Elizabeth Donna https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745240738 - Electrode potential 
 1. Redox (OIL , RIG)
 2. Unreactive metal : Further to the right - easier to reduce
 3. Reactice metal : Further to the left - difficult to reduce
 4. Half eq *in terms of reduction - electrons on the left*
 5. Standard hydrogen electrode : E=0.00V
 6. Need to know how to draw : Standard condition (298K) 
     *Platinum wire
     *Glass bell
     *Supply of hydrogen 
     *Platinum electrode 
     *H+ , 1.00 mol dm^-3
     *Have hole (inside water) 

- Electrode potential and redox reactions
 1. Must be in reduction form (gain of e-)
 2. V= Positive (go to right)- unreactive , V= Negative (go to left) - reactive 

- Electrochemical cell 
 1. Do not need power supply
 2. Salt bridge : Separate ions and connect the circuit 
 * Filter paper - soak in saturated solution of KNO3 or NaNO3 
 * AgNO3 -> Ag+ + NO3- , Zn2+ + Cl- , AgCl (participate) 

- Measuring standard eletrode potentials 
 1. Metal / metal ions half cell
 * loses electrons : Negative terminal 
 * Gain electrons : Positive terminal 
 2. Non- metal / non metal ion half cell
 3. Ion/ ion cell half cell 
 * MnO4- (aq) + 8H+ (aq) + 5e- <=> Mn2+ (aq) + 4H2O (l) 

- Using E⁰
 1. Standard cell potential can be calculated for two half cells 
 2. Don't (times/multiply) voltage , only change sign for voltage ]]> 2021-09-16 07:35:09 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745240738 Benedict JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745261849 Today, i learnt about Electrode potential.

The voltage shows which metal is more reactive and unreactive. The more unreactive one is more positive and is easier to reduce. The more reactive metal is more negative and is harder to reduce. The one with the more positive voltage is the one that is gaining electrons while the more negative one is the one giving electrons. We can use this to determine which one is the positive side and negative side in the circuit.

Calculating the voltage is simple. Use the table to get the values and add them normally after switching signs. The voltage does not scale and does not need to be balanced along with the electrons.

I also learnt about the 3 types of half-cells and how to draw them.
- Metal/Metal ion
-Non-Metal/Non-Metal ion
-ion/ion
A salt bridge is needed to complete the circuit

I learnt alot from the lesson and i will need to revise on the detaisl and conditions for all these reactions to apply. The lesson was good and easy to understand.]]> 2021-09-16 07:45:21 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745261849 Josh JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745370824 Equation for potential difference needs to be in reduction form. The more unreactive one is the more positive one which is easier to reduce. The one that is more reactive is more negative which is harder to reduce. The positive one gains electrons and the negative one loses electrons. 

To get voltage we need to use the table and switch the signs in the equation. 

Salt bridge is the movement of ions between the two half cells.

3 types of half-cells
- Metal/Metal ion (Zn or Zn2+)
- Non Metal/Non Metal Ion (Cl2 or Cl-)
- Ion/Ion (Fe2+ or Fe3+)

This lesson was pretty good and I understood a lot. The teaching is great and it is very clear and thorough.]]> 2021-09-16 08:35:58 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745370824 Thomson JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745568701 Redox
oxidation is gain reduction is lose electron
(more positive is reduction)
(more negative is oxidation)

Standard hydrogen electrode diagram and use to determine electrode potential along with half cell diagram

Electrochemical cell with metal or non metal ion diagram 

 Salt bridge cannot use solution which can form precipitate

Electrode potential equation does not have to be multiplied or divided

]]> 2021-09-16 10:25:46 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1745568701 Jasmine JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1746181217 Learnt about :
- electrode potential ( more positive goes to right, more negative goes to left )
- salt bridge : functions and how to use
-  electrochemical cell Vs electrolysis : no need power supply while electrolysis needs power supply 
- 3 types of half cells : 
1. metal and metal ions 
2. non metal and non metal ions
3. ion and ion 
- electrode potential equation should not be multiplied ( voltage only )
- signs interchanged when equilibrium is to the left 

need to revise more on :
drawing the electrochemical cells and half cell diagrams

teaching :
very detailed and easy to understand ]]> 2021-09-16 14:37:50 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1746181217 Catherine JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747311661
  • electrode potential (more positive move right, more negative move left)
  • electrochemical cell don’t need to use electricity
  • salt bridge soaked in solution of potassium nitrate
  • 3 types of half cells

    • need to revise more on: drawing half cells

    ]]>     2021-09-17 00:56:52 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747311661     Audrey JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747415552 Redox
    Oxidation -> loss of electrons
    Reduction -> gain of electrons
    (OIL RIG)

    Electrode potential
    - more positive, more right (reduced)
    - more negative, more left (oxidised)

    To calculate V generated :
    Change the sign of E
    No need to multiply if for example 2X+ needed

    Salt bridge - movement of ions between 2 half cells

    Types of half cell :
    - metal metal
    - nonmetal nonmetal
    - ion ion

    Need to revise more on :
    Calculating electrode potential
    Drawing diagrams]]>     2021-09-17 01:37:45 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747415552     Jacelyn KJS JC2M https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747579905 Redox
    Reduction - gain of electrons
    Oxidation - lose electrons

    Electrode potential positive/ higher, easier to reduce
    The ion with less negative/ positive electrode potential is oxidizing agent
    Cathode attracts cations and anode attracts anions
    Reduction occurs in cathode, oxidation occurs in anode

    ]]>     2021-09-17 02:41:55 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747579905     Kassapa KJS JC2M https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747587871 oxidation - loss of electron
    reduction - gain of electron

    Faraday - electriv charge carried by 1 mol of electron or charged ion

    standard hydrogen electrode
    one of the several types of half cell that can be used as reference electrode.]]>     2021-09-17 02:45:03 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747587871     Ladesha KJS JC2M https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747599896 Always remember: OIL RIG

    Equilibrium lies on:
    - further to right for unreactive metals
    - further to left for reactive metals

    Electrode potential values -> how easy it is to gain electron
    A trick (for equations in reduction form):
    - more positive voltage, equilibrium goes right
    - more negative voltage, equilibrium goes left / behind

    Reducing agent reduces others but gets itself oxidised, while Oxidation agent oxidises others but gets itself reduced.]]>     2021-09-17 02:49:51 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747599896     Nesya JC2M https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747621346 During this lecture, I learnt about electrode potential, redox reactions, half cells, and salt bridge. We can use the mnemonic 'OIL RIG' to remember redox; oxidation is loss of electrons and reduction is gain of electrons. The cathode attracts cations (+) and the anode attracts anions (-). When electrode potential is positive, there is a greater tendency for the reaction to proceed to the right (reduction). Likewise, when electrode potential is negative, there is a greater tendency for the reaction to proceed to the left (oxidation). There are three types of half cells; metal/metal, non-metal/non-metal, and ion-ion. To complete the circuit, a salt bridge, where ions move between two half cells, is needed.

    Need to revise more on: Drawing electrochemical diagrams.

    Overall, the lecturer managed to explain the topic in a detailed manner, including clearing up doubts. The lecturer went through the topic at a fine pace, and the explanations, including presentations, notes, diagrams, and voice were easy to follow and understand. Lecture archives are also available for personal revision.]]>     2021-09-17 02:58:52 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1747621346     Ella JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1748336024
  • Oxidation and Reduction can be remembered as OIL RIG (ox: loss of e, red: gain of e)
  • Redox Equilibrium: Rate of e gain = e loss
  • Reactive metals: Eq lies to left (ion)
  • Unreactive metals: Eq lies to right (metal)
  • EP cannot be measured directly, only the PD can be measured. The relative system is a hydrogen fuel cell.
  • Black platinum electrode is in contact with both H+ and H2.
  • Undergo under standard conditions (1 atm, 298K, 1 mol/dm3)
  • EP of HFC is 0
  • The hole in HFC is placed below the solution level to prevent H2 from escaping without reacting.
  • Eq must be in reduction form. When EP (+), the equation shifts to the right.
  • Reducing agent: Reduces others, but it itself will get oxidised.
  • Electrochemical cell has two metals with different reactivities so no power supply is necessary.
  • Salt bridge id a strip of filter paper that completes the equation, maintains ionic balance and allows ionic flow. 
  • Electrons will only flow in the external circuit (the wires).
  • Electrolysis is a redox reaction.
  • When the equation is reversed, the EP symbol is switched.
  • When AgNO3 is used in the presence of Cl-, AgCl, a white precipitate will be formed and the reaction flow will be blocked.
  • EP can be measured with three setups M/M, NM/NM, I/I.
  • H2 cell releases e and Cu electrode accepts it. So H2 (-), Cu (+) terminal.
  • H2 cell loses e, Cl2 accepts so H2 (-), Cl2 (+)
  • I2 is a solid, Pt must be in contact with both I2 and I-.
  • Must memorise or be able to derive MnO4- (aq) + 8H+ (aq) + 5e <—> Mn2+ (aq) + 4H2O, but can be found in Data Booklet.
  • Two beakers: MnO4-, Mn2+, H+ in B1 and H+ in B2.
  • EP (Ag+ red) = EP (2Ag+ red)
  • Those who lose e- will become the (-) electrode.

    • ]]>     2021-09-17 10:13:45 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1748336024     Keira JC 2 Grace https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1748361352 I learnt that 
    - half equation is always written in reduction
    - we use standard hydrogen electrode to compare the potential difference
    - standard electrode potential: conc. of ions at 1moldm-³, temp. of 298K, gases at 1atm(101kPa)
    - E value more positive = reaction will go right
    - metals that gain electrons tend to be unreactive and a poor reducing agent
    - ions are moved around salt bridge
    - to count E value, add the respective E value from each reaction
    - E value should not be multiplied
    - salt bridge ions should not react with the ions from the substances
    - positive terminal is anything that gains electrons 
    - non metal/non metal half cell
    1. for gaseous atoms, platinum cell fully in contact with the gas
    2. half of the platinum in contact with the solid and half with the aqueous solution.

    I need to practice drawing the half cell and the diagrams of half cell for measuring between metal/metal ion, non metal/non metal ion and ion/ion cell.]]>     2021-09-17 10:33:47 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1748361352     Jonathan JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1749943276 I learnt about the conditions for reduction and oxidation, the half equation will always be reduction, and I also learnt about electrode potentials, and how to form equations for the anode and cathode.]]> 2021-09-18 03:19:03 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1749943276 michelle jc2grace https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751261472 i learnt that the more reactive, the position of the equilibrium will be shifted to the left. more positive = equation will go to the right. more negative= equation will go to the left. most negative means it goes through oxidation and is the best reducing agent. more negative means it loses electrons and is hardest to reduce.

    ]]>     2021-09-19 06:36:44 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751261472     Jennifer JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751378716 Electrical Potential
    - Voltage more positive (+), shift to the right. Best oxidizing agent
    - Voltage more negative (-), shift to the left. Best reducing agent

    Salt Bridge
    - Filter paper
    - maintains ionic balance
    - Movement of ions between 2 half cells
    - Completes the circuit

    Half cells
    - Metal/Metal ion
    - Non-metal/Non-metal ion
    - Ion/Ion

    ]]>     2021-09-19 08:48:18 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751378716     Kevin JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751383131 1. Electrode potential, more + goes to the right, more - goes to the left. More + gains electrons, more - lose electrons
    2. Ions move around salt bridge
    3. To calculate the Voltage, no need to multiply by a number to balance the electrons.
    4. 3 types of half cell : metal and metal ions, non metal and non metal ions, Ions and Ions

    ]]>     2021-09-19 08:52:54 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751383131     sharon jc2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751423022 Electrode potential
    • Position of equilibrium differs for different combination of metals placed in solutions of their ions
    • Cannot measure directly the electric potential of the metal and metal ions in solution
    • Can measure the difference in potential between metal/metal ions system and another system (Cu and Mg with salt bridge thingy)
      • Comparing with standard hydrogen electrode
    • What is an electrical double layer?
      • Due to electrical double layer, we cannot measure the absolute electrical potentials by the formation of the double layer. 

    Electrode potential and redox reaction
    • More positive, go to the right
    • Most reactive means can lose electron easily
    • Metal on the right is relatively unreactive and a relatively poor reducing agent 
    • Positive : poor reducing agent (metals on the right)
    • Negative : good reducing agent (metals on the right)
    • Salt bridge can be made from a strip of filter paper (or other iner

    Measuring standard electrode potential
    • metal/metal ion half cell
    • Non-metals and non-metal ions
    • ion/ion cell half cell/
    ]]>     2021-09-19 09:33:03 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751423022     Juliano JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751428381 More positive value for E means easier to be reduced. 
    Electrons move around at the external circuit, ions move around at salt bridge. 
    Voltage no need to multiply by any number when there is more mole of ions. 
    The way to draw different electrode.]]>     2021-09-19 09:38:41 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751428381     Michael jc2t https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751433752 Electrolysis is a redox reaction. Oxidation is loss of electron. Reduction is gain of electron. Redox equilibrium is established when the rate of electron gain equals to the rate of electron loss. Voltage cannot be measured directly but the potential difference between metals can be measured. Salt bridge is used to connect the circuit and allowing ions to move. Salt bridge is usually potassium nitrate or sodium nitrate. Three type of half cells: metal/metal ion half cell, non metal/non metal ion half cell, ion/ion cell half cell.]]> 2021-09-19 09:44:06 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751433752 Frederic https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751439198 Electrode potential
    • Position of equilibrium differs for different combination of metals placed in solutions of their ions
    • Cannot measure directly the electric potential of the metal and metal ions in solution
    • Can measure the difference in potential between metal/metal ions system by comparing two standard hydrogen electrode
    • What is an electrical double layer?           it is an interface between an electrode and an electrolyte that forms a layer of positive ions that is covered by negative ions due to attraction

    Electrode potential and redox reaction
    • More positive, to the right
    • Most reactive metal can lose electrons easily(metal)
    • more negative, to the left
    • Salt bridge allows the movement of ions

    Measuring standard electrode potential and how to draw
    • metal/metal ion half cell
    • Non-metals and non-metal ions
    • ion/ion cell half cell/
    ]]>     2021-09-19 09:49:18 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751439198     Megan Jc2 T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751452145 In this lecture I learnt :
    - More reactive metals are harder to reduce 
    - Less reactive metals are easier to reduce
    - When calculating the standard cell potential, we don’t need to multiply the electrode potential to the numbers used to eliminate the electrons.
    -Three types of half cells : 1. Metal/Metal 2. Non metal/ Non metal 3. Ion/ion
    - The standard conditions of standard hydrogen electrode cells are : 1. Conc. Of ions at 1.00 mol/dm^3 2. Temperature at 298K 3. Gases at pressure of 1 atm 4. The value of the electrode potential of the half cell is measured relative to the standard hydrogen electrode.

    The lecture made the chapter easier to understand. Very good teaching style 👍

    ]]>     2021-09-19 10:02:16 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751452145     Angela JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751452948 - OIL RIG (oxidation: loss of electrons, reduction: gain of electrons)
    - for reactive metals, equilibrium lies further to the left and they are good reducing agents 
    - for unreactive metals, equilibrium lies to the right and they are poor reducing agents 
    - we cannot measure directly the electric potential of the metal and metal ions in a solution
    - electrolysis needs a power supply to move ions, electrochemical cell no need 
     - salt bridge separates the electrolytes and allows movement of ions
     - salt bridge is filter paper soaked in saturated potassium nitrate solution 

    Measuring standard electrode potential
    - metal/metal ion half cell
    - non-metal/non-metal ion half cell 
    - ion/ion half cell
    ]]>     2021-09-19 10:03:11 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751452948     Ashley JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751457069 I learnt how to... 

    Electrode Potential ++ (half) Reactions: 
    - Always write in reduction form 
    - Always use standard conditions! (298K, pressure of 1 atm, concentration of 1 mol dm^-1) 
    - Differences in EP can only be compared, not measured directly 
    - The more positive it is, the more unreactive the metal is, harder to be oxidised——good oxidising agent. 
    - The more negative it is, the more receive it is, more easily oxidised—— good reducing agent. 
    - To put it simply, the electrode with the more positive EP will be the positive terminal. 
    - To put it simply, the electrode with the more negative EP will be the negative terminal, bc it loses electrons. 

    Electrochemical Cell: 
    - Does not need power supply 
    - Salt bridge (filter paper soaked in solution of KNO3 or NANO3): Separate ions and connects the circuit 
    *Electrolysis is different because it is a redox reaction 


    Voltage: 
    1. Get your reactions in reduction forms, compare their EPs
    2. Rearrange the half-reaction with the more negative EP (just reverse it). Then also multiple the EP by -1 
    3. Add up the EP (no multiplying or dividing the EP) 
    4. balance the half-equation into one reaction

    Three types of Half-cells:
    - Metal/Metal ion
    - Non Metal/Non Metal 
    - Ion/Ion

    I feel like I need to memorise and revise more on the half-cell diagrams? As well as really understand why certain solutions cannot be used. 

    The lesson was great, there was also YT videos of the lectures for personal revisions as well.]]>     2021-09-19 10:07:14 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751457069     Yeewen JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751467992 -Electron lost is oxidation while electron gain is reduction 

    -if electrode potential is positive, the equation moves more towards the right.

    -if electrode potential is negative, the equation moves more towards the left

    -Salt bridge is used to transfer the ions

    -When calculating we do not multiply the V when balancing the equations.
    ]]>     2021-09-19 10:18:20 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751467992     Dylan JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751480910 Redox Reaction
    OIL RIG
    oxidation - loss of electrons
    reduction - gain of electrons

    Electrode Potential 
    • position of equilibrium differs for different combinations of metals placed in solutions of their ions
    • the electric potential of the metal and metals ions in solution cannot be measured directly, however, we can measure the difference in potential between the metal/metal ions system and another system (standard hydrogen electrode, E = 0.00V)
    • half-reaction is always written in reduction form

    Standard Electrode Potential (E°) 
    • The standard electrode potential for a half-cell is the voltage measured under standard conditions with a standard hydrogen electrode as the other half-cell.

    Conditions:
    • Concentration of ions at 1.00 mol dm-3
    • Temperature of 25 °C (298K)
    • Pressure of 1 atm (101kPa)

    Electrode Potential and Redox Reactions
    • Electrode potential values give us an indication of how easy it is to reduce a substance
    • if the E value is more positive, more right (reduced, good oxidizing agent)
    • if the E value is more negative, more left (oxidised, good reducing agent)

    How to calculate the voltage
    • Use the table to get values in which afterwards, you have to switch signs and just add them. (voltage does not need to be balanced) 

    Salt bridge
    • can be made from a strip of filter paper (or other inert porous material) soaked in a saturated solution of potassium nitrate. 
    • movement of ions between 2 half cells

    Types of half cells (also learnt how to draw them):
    • metal/ metal ion
    • non-metal/ non-metal ion
    • ion/ ion

    Overall, I learnt a lot from today's lecture and I think I need to revise more on drawing the half cells. Other than that, the teaching was clear and easy to understand as usual! :D

    ]]>     2021-09-19 10:31:09 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751480910     Nathan L https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751507507 I learned about Redox reaction which consists of both oxidation as well as reduction.

    Or in other words OILRIG, Oxidation Is Loss of electrons Reduction Is Gain of electrons.

    I also learned about electrode potential. To determine the equilibrium of the equation, we have to look at the electrode potential whether it is positive or negative. The higher the value, the easier it is reduced. The electrons travel through a "Salt bridge" to move. Drawing the circuits will also be different for metal and metal ion, ion and ion half cell, as well as non-metal and non-metal half cell.

    ]]>     2021-09-19 11:00:07 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751507507     Geoffrey Jc2Truth https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751537932 Learnt about 
    -OIL RIG
     Oxi is loss
     Reduc is gain

    -Electrode Potential where 
    - more positive, more right (reduced)
    - more negative, more left (oxidized) 

    Salt bridge
    -Which can be made from a strip of filter paper (or other inert porous material) soaked in a saturated solution of potassium nitrate.and allows movement of ions between 2 half cells

     Half cells
    - Metal/Metal ion
    - Non-metal/Non-metal ion
    - Ion/Ion
    Need to memorize and revise more on the half-cell diagrams ahd reactions

    Lesson easy to understand

    ]]>     2021-09-19 11:32:57 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751537932     Jordan Jc2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751562975 I learnt about how to find the electric potential of an electrochemical cell and learnt how it indicates whether the substance is easier to reduce or not. The more positive the voltage is, the easier it is to reduce the ion on the left while the more negative it is, the harder it is to reduce the ions on the left. I also pearnt that excluding the hydrogen half-cell, there are metal/metal ion half cell, non-metal/non-metal ion half cell and lastly ion/ion half cell. Lastly I learnt that the salt bridge is usually made of KNO3 in order to prevent inefficiency.]]> 2021-09-19 11:57:43 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751562975 Nicholas https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751577755 From this lecture, I learnt that 
    • Metals are more reactive when they can easily lose electron, good reducing agent, bad oxidising agent.
    • Half equation must be in form of reduction.
    • For reactive metals, the equilibrium lies further to the left (lose electron, oxidised). For unreactive metals, the equilibrium lies further to the right (gain electron, reduced).
    • We cannot measure directly the electric potential of the metal but we can measure the difference in the potential between metal/metal ions system or other system.
    • Standard hydrogen electrode : E = 0.00V, 2H+ + 2e ⇌ 2H2.
    • Standard Electrode Potential : concentration of ions 1.00 mol dm^-3, 298K, gas must be in 101kPa, use Standard hydrogen electrode.
    • Electrolysis use battery, power supply, to move the ions. Electrochemical cell use the potential difference to move the electron and ion to move.
    • Salt bridge is for ions.
    • The E value is not affected in magnitude when an equation is being balanced, only the sign when switching sides.
    • 1. Switch the equation to the LHS/RHS to cancel the electrons, this will change the sign of E value. 2. Add the E values together to get the total E value.
    • Silver nitrate cannot be used when ZnCl2 is used because the Ag+ will react with Cl- to form AgCl ppt that will block the salt bridge. Other nitrates are allowed.
    • 3 types of half cell : metal/metal ion, non metal/non metal ion, ion/ion half cell.
    • Need to be careful for half cells like MnO4-/Mn2+. MnO4-(aq) + 8H+(aq) + 5e ⇌ Mn2+(aq)+ 4H2O(l). H+ ion need to be included in the solution. 
    • Positive pole is the half equation that has the more positive/ less negative E value.
    ]]>     2021-09-19 12:11:45 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751577755     MichelleV Jc2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751588744 1. I revised about OIL RIG, (oxidation is loss of electron, reduction is gain of electron)

    2. Equilibrium lies on the left for reactive metals and right for unreactive metals.

    3. Faraday is electric charge carried by 2 mol of electron or charged ion

    4. Electrode potential (for reduction):
       - equilibrium goes right for more positive voltage
       - equilibrium goes left for more negative voltage

    5.  How to draw the half cell diagrams, electrochemical cells

    6. Salt bridge is the movement of ions between 2 fall cells.

     
    ]]>     2021-09-19 12:21:22 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751588744     Justin JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751593584 I learnt that more reactive metals have equilibrium lying closer to the left and unrective lies closer to the right. We can measure the the potential difference from the two systems but cannot measure the voltage directly. 


    Standard electrode potential
    conditions
    -1mol/dm^3
    -25°C
    -1 atm

    If the voltage is more posititve than metals on the left are  poor reducing agent and if the voltage is negative, metals on the left are good reducing agents.

    When reversing an equation, the voltage value is muliplied by -1

    Positive terminal is the electrode that receives electrons.
    Negative terinals is the electrode that loses electrons.






    ]]>     2021-09-19 12:25:56 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751593584     Arwen_JC2 T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751595322 Recalled: 
    • OIL RIG (Oxidation is loss of electrons, reduction is gain of electrons.)
    • use standard conditions (298K, 1.00 mol/dm3, 1 atm)
    • more positive electrode potential - metal more unreactive (harder to be oxidised - oxidising agent); more negative electrode potential - metal more reactive (easily oxidised - reducing agent)
    • electrode potential cannot be measured directly, can only be compred

    Cells:
    • salt bridges - made from porous materials, e.g. filter paper, soaked in KNO3 or NaNO3; connects circuits through separation of electrolytes
    • three half-cells:
      • metal-metal ion
      • metal-non-metal ion
        • solid
        • gas
      • ion-ion ion

    This chapter is quite nice. I'll have to remember the half-equations better and revise content from chapter seven.
    ]]>     2021-09-19 12:27:30 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751595322     Raphael JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751604419 OIL RIG:
    Oxidation is loss of electrons
    Reduction is gain of electrons

    Electrode Potential:
    More positive is reduced
    More negative is oxidized

    Salt bridge:
    Filter paper dipped in potassium nitrate used to transfer ions

    Half cells:
    Metal/Metal ion; Non-metal/Non-metal ion; Ion/Ion

    Conditions: 
    Concentration of ions is 1.00 mol dm-3
    Temperature is 25 degrees Celcius / 298 Kelvin
    Pressure of 1 atm]]>     2021-09-19 12:34:48 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751604419     Chris JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751616634 What I learnt:
    How electrolysis works (redox, electrode potential)
    How an electrochemical cell works (negative ions go to anode, positive to cathodes, flow of electrons and ions, structure of different types of half cells, etc)
    How to understand and calculate electrode potential and potential difference for cells.]]>     2021-09-19 12:44:26 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751616634     Josh JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751619220 From the video I've learnt :
    - electrode potentials tell us which element is reduced and which element is oxidised inthe redox reaction with electrochemical reactions, such that in electrolysis.
    - the more positive the electrode potential, the more likely it's ions will be reduced
    - the more negative the electrode potential, the more likely it's atoms will be oxidised
    - electrode potentials can shift the position of the redox equilibrium

    Electrochemical cells = modern day batteries

    Electrode potentials using the standard hydrogen electrode potential

    I've learnt how to draw
    - metal/metal ion half cells
    - non metal/metal ion half cells
    - ion/ion half cellscell]]>     2021-09-19 12:46:20 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751619220     Jacksen JC2T https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751626223 Redox equilibrium = Harder to lose electron, equilibrium at right, easier to lose electron, equilibrium at left
    Electrode potential = measurer volt to see how easy it is to reduce substance, more positive volt, easier to reduce, less positive volt harder to reduce. Later used to calculate volt difference between cell.
    E standard (298K,1mol/dm3,1atm)
    Salt bridge
    Half cell 
    - metal/metal ion 
    - non metal/non metal ion
    -ion/ion ]]>     2021-09-19 12:51:15 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751626223     Wilson https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751666403 From this lecture I revised about OILRIG which directly stands for oxidation is losing, reduction is gaining. This means that when you lose an electron, it is oxidation and the opposite would mean reduction. I also learnt about the ability of metals to lose electrons is directly linked to their reactivity. There are also 3 types of half cells that we learnt which are metal/metal, non-metal/non-metal and ion/ion. We also learnt about the standard hydrogen electrode.]]> 2021-09-19 13:17:00 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751666403 Cleantha https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751680209 The more positive the voltage will be, the easier it is to reduce the ions on the left

    Salt Bridge (a strip of filter paper soaked in potassium nitrate) is needed to be inserted in both beakers 

    Learned more about the three types of half cell: metal - metal ion half cell,
    non metal - non metal ions and ion - ion half cell
    ]]>     2021-09-19 13:25:34 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751680209     James JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751692334 learnt that more positive an electrode potential the more ions are reduced, the more negative the more ions oxidised.

    the standard electrode potential is 
    -1mol/dm^3
    -25°C
    -1 atm

    salt bridge is a filter paper dipped in potassium nitrate for transferring ions

    need to revise more on the parts of electrolysis and the steps for it including flow of electrons and ions 

    ]]>     2021-09-19 13:32:41 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1751692334     Earlene JC2G https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1752258560 1. movement of electrons always occurs in the external circuit

    2. less reactive metal, harder to oxidise, easier to reduce, poor reducing agent

    3. more reactive metal, easier to oxidise, harder to reduce, good reducing agent

    4. half equation has to be in reduction form

    5. flipping the equation changes the sign of the E standard

    6. electric potential cannot be measured directly, instead we can compare the difference between a metal/metal ions system and another system (normally standard hydrogen electrode which has potential difference of 0.00V)

    7. electrical double layer is a double layer between the charges and the electrode that will cause a potential difference

    8. standard hydrogen electrode (must know how to draw the set up)

    9. when potential difference is + then go to the right, when - then go to the left

    10. salt bridge is a filter paper soaked in a saturated solution of potassium nitrate, it allows movement of ions

    11. standard electrode potential for a half-cell is the voltage measured under standard conditions with a standard hydrogen electrode as the other half-cell

    12. measuring standard electrode potentials (metal/metal half cell, non-metal/non-metal half cell, ion/ion half cell)]]>     2021-09-19 19:21:10 UTC https://padlet.com/pooganeswaripiks/1ezpnb7abwwxaytr/wish/1752258560