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Chemistry-Organic Chemistry. > CHEMISTRY, TOPIC FOURTEEN, 14. REDOX II. > Flashcards

CHEMISTRY, TOPIC FOURTEEN, 14. REDOX II. Flashcards

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1
Q

ELECTROCHEMICAL CELLS.

A

A CELL HAS TWO,2, HALF-CELLS.
THE TWO,2, HALF CELLS ARE CONNECTED WITH A SALT BRIDGE.
SIMPLE HALF CELLS, WILL CONSISTS OF A METAL THAT ACTS AS AN ELECTRODE, AND A SOLUTION COMPOUND CONTAINING THAT METAL, FOR EXAMPLE THE METAL COULD BE COPPER, Cu, AND THE SOLUTION WOULD BE COPPER SULFATE, CuSO4.
THESE TWO,2, HALF CELLS WILL PRODUCE A SMALL VOLTAGE IF CONNECTED INTO A CIRCUIT.
E.G.= BECOME A BATTERY OR A CELL.

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2
Q

WHY DOES A VOLATGE FORM, WHEN USING ELECTROCHEMICAL CELLS?

A

WHEN THE TWO,2, HALF CELLS ARE CONNECTED TOGETHER, ONE OF THE HALF CELLS WILL HAVE MORE OF A TENDENCY TO OXIDISE, SO LOOSE ELECTRONS, TO FORM A POSITIVE ION.
THIS MEANS THAT THEY WILL ALSO RELEASE ELCTRONS AT A GREATER TENDENCY, IF THEY OXIDISE AT A GREATER TENDENCY.
MORE ELCTRONS WILL THEREFORE BUILD UP AT THIS ELECTRODE, IN COMPARRISION TO THE OTHER ELECTRODE.
A POTENTIAL DIFFERENCE IN CREATED BETWEEN THE TWO,2, ELECTRODES.
THE ONE THAT OXIDISES AT A GREATER TENDENCY, WILL BE THE NEGATIVE TERMINAL, WHILST THE OTHER WILL BE THE POSITIVE TERMINAL.

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3
Q

HOW DO WE MEASURE THE POTENTIAL DIFFERENCE, OF AN ELECTROCHEMICAL CELL?

A

THIS POTENTIAL DIFFERENCE IS MEASURED WITH A HIGH RESISTANCE VOLTMETER, AND IS GIVEN THAT SYMBOL, E.

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4
Q

WHY DO WE USE A HIGH RESISTANCE VOLTMETER?

A

WE USE A HIGH REISSTANCE VOLTMETER, TO MEASURE THE POTENTIAL DIFFERENCE.

THE VOLTMETER, NEED TO BE OF A VERY HIGH RESISTANCE TO STOP THE CURRENT FROM FLOWING IN THE CIRCUIT.
IN THIS STATE IT IS POSSIBLE TO MEASURE THE MAXIMUM POTENTIAL DIFFERENCE, E.

THE REACTION WILL NOT BE OCCURING BEACUSE THE VERY HIGH RESISTANCE VOLTMETER, STOPS THE CURRENT FROM FLOWING.

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5
Q

SALT BRIDGE, WHAT IS IT AND WHY DO WE USE IT, IN AN ELECTROCHEMICAL CELL?

A

THE SALT BRIDGE IS USED TO CONNECT UP THE CIRCUIT.
THE FREE MOVING IONS, CONDUCT THE CHARGE.

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6
Q

THE SALT BRIDGE, WHAT IS IT MADE FROM?

A

A SALT BRIDGE IS USUALLY MADE FROM A PIECE OF FILTER PAPER, OR MATERIAL, SOAKED IN A SALT SOLUTION.
USUALLY POTASSIUM NITRATE, OR POTASSIUM CHLORIDE.

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7
Q

THE SALT BRIDGE, THE SALT USED.
WHAT SHOULD IT BE?

A

THE SALT SHOULD BE UNREACTIVE WITH THE ELECTRODES AND ELECTRODE SOLUTION.

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8
Q

THE SALT BRIDGE, THE USE OF A WIRE.

A

A WIRE IS NOT USED, BEACUSE THE METAL WIRE WOULD SET UP ITS OWN ELECTRODE SYSTEM WITH THE SOLUTIONS, AND WIRE DO NOT ALLOW THE FLOW OF IONS.

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9
Q

WHAT HAPPENS IF CURRENT IS ALLOWED TO FLOW, IN AN ELECTROCHEMICAL CELL?

A

IF THE VOLTMETER IS REMOVED, AND REPLACED WITH A BULB OR IF THE CIRCUIT IS SHORT CIRCUITED, A CURRENT FLOWS.
THE REACTIONS WILL THEN OCCUR SEPARTELY AT EACH ELECTRODE.
THE VOLTAGE WILL FALL TO ZERO,0,
AS THE REACTANTS ARE USED UP.

THE MOST POSITIVE ELECTRODE, WILL ALWAYS UNDERGO REDUCTION.
SO IT WILL GAIN ELECTRONS.
SO IT WILL GO FROM A POSITIVE ION, TO
THE METAL WITHOUT A CHARGE.

THE MOST NEGATIVE ELECTRODE, WILL ALWAYS UNDERGO OXIDATION.
SO IT LOOSE ELECTRONS, AND BECOME A POSITIVE IONS.

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10
Q

CELL DIAGRAMS.

A

ELECTROCHEMICAL CELLS CAN BE REPRESENTED BY A CELL DIAGRAM.
.=REFER TO YOUR NOTES FOR THIS.

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11
Q

AN ELECTROCHEMICAL CELL.
SYSTEMS THAT DO NOT INLCUDE METALS.

A

IF A SYSTEM, DOES NOT INCLUDE A METAL, THAT CAN ACT AS A SINGLE ECLETRODE, THEN A PLATNIUM ELECTRODE MUST BE USED AND INCLUDED IN THE CELL DIAGRAM.

IT PROVIDES A CONDUCTING SURFACE FOR ELECTRON TRANSFER.

A PLATNIUM ELECTRODE IS USED, BEACUASE IT IS UNREACTIVE, INERT, AND CAN CONDUCT ELECTRICITY, ELECTRICALLY CONDUCTIVE.

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12
Q

NO METAL IN THE SYSTEM, WHAT IS IT LACKING?

A

IF THERE IS NO METAL IN THE SURFACE, THERE IS NO SOLID CONDUCTING SURFACE, SO A PLATNIUM , Pt, ELECTRODE MUST BE USED.
.= REFER TO NOTE, TO SEE THE CELL DIAGRAM FOR THIS.

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13
Q

IF THE SYSTEM CONTAINS, SEVERAL SPECIES.

A

IF THE SYSTEM CONTAINS SEVERAL SPECIES, THE IN THE CELL DIAGRAM THE BALANCING NUMBER, H^+ IONS, AND H2O CAN BE LEFT OUT.
.= REFER TO NOTE, TO SEE THE CELL DIAGRAM FOR THIS.

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14
Q

MEASURING THE ELECTRODE POTENTIAL OF A CELL.
WHAT DO WE MEASURE?

A

IT IS NOT POSSIBLE, TO MEASURE THE ABSOLUTE POTENTIAL OF A HALF ELECTRODE ON ITS OWN.
IT IS ONLY POSSIBLE TO MEASURE THE POTENTIAL DIFFERENCE BETWEEN TWO,2, ELECTRODES.

TO MEASURE IT, IT HAS TO BE CONNECTED TO ANOTHER HALF-CELL OF KNOWN POTENTIAL, AND THE POTENTIAL DIFFERENCE BETWEEN THE TWO HALF-CELLS, IS MEASURED.

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15
Q

THE STANDARD HYDROGEN ELECTRODE.

A

THE STANDARD HYDRGOEN ELECTRODE, SHE, IS USED AS A REFERNCE TO MEASURE STANDARD ELECTRODE POTENTIALS, E THETA.

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16
Q

WHEN ARE ELECTRONS TRANSFERRED?

A

ELECTRONS ARE TRANSFERRED WHEN REDUCTION AND OXIDATION OCCURS.
OILRIG.

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17
Q

REDUCING AND OXIDISING AGENTS.

A

A REDUCING AGENT, WILL IN FACT LOOSE ELECTRON.

AN OXIDISING AGENT, WILL IN FACT GAIN ELECTRONS.
THE OPPOSITIE OF OILRIG.

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18
Q

HALF CELL.

A

A HALF CELL, IS ONE HALF OF AN ELECTROCHEMICAL CELL.
THEY CAN BE CONSTRUCTED OF A METAL DIPPED IN ITS IONS, OR A PLATNIUM ELECTRODE WITH TWO,2, AQEOUS IONS.

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19
Q

HOW IS AN ELECTROCHEMICAL CELL CREATED?

A

AN ELECTROCHEMICAL CELL, IS CREATED BY JOINING TWO,2, DIFFERENT HALF CELLS TOGETHER.

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20
Q

WHAT ARE ELECTROCHEMICAL CELLS, MADE UP OF?

A

ELECTROCHEMICALL CELLS ARE MADE OF TWO,2, HALF CELLS JOINED TOGETHER BY A WIRE, VOLTMETER, AND A SALT BRIDGE.

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21
Q

HOW DO ELECTROCHEMICAL CELLS WORK?
REACTIONS.

A

WHEN WE CONNECT TWO,2, HALF CELLS WE GET ONE SIDE UNDERGOING A REDUCTION PROCESS AND THE OTHER UNDERGOING AN OXIDATION PROCESS.
ESSENTIALLY, WE HAVE A REDOX REACTION.

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22
Q

ELECTROCHEMICAL CELL, ELECTRON FLOW.

A

ELECTRONS FLOW FROM A MORE REACTIVE METAL, TO A LESS REACTIVE METAL.

23
Q

ELECTROCHEMICAL CELL, OBSERVATION.

A

THE ELECTRODE OF THE METAL, THAT IS IN FACT THE MOST REACTIVE, WILL BECOME THINNER.

THE ELECTRODE OF THE METAL THAT IS THE LEAST REACTIVE, WILL IN FACT BECOME THICKER.
AS IT ACCEPTS AND RECIEVES THE ELECTRONS PRODUCED BY THE MORE REACTIVE METAL.
SO, IT WILL BE REDUCED.
REDUCTION HAS OCCCURED.

24
Q

ELECTRODE POTENTIAL.
WHAT IS IT, AND WHERE IS IT FOUND?

A

EACH HALF CELL, HAS AN ELECTRODE POTENTIAL, E THETA, THE VALUE IS MEASURED IN VOLTS.
IT TELLS US HOW EASILY THE HALF CELL, GIVES UP ELECTRONS.
SO, IS OXIDISED.

25
Q

REACTION TYPE, THE HALF CELLS.

A

THE TWO,2, HALF CELLS EACH HAVE A REVERSIBLE REACTION.

26
Q

HOW DO WE WRITE THE EQUATIONS, OF AN ELCTROCHEMICAL CELL?

A

IN ELECTROCHEMICAL CELLS, WE ALWAYS WRITE THE EQAUTIONS IN THE, ‘REDUCED FORM”.
THIS MEANS WE ALWAYS SHOW THE EQUATIONS WITH REDUCTION IN THE FORWARD DIRECTION.

27
Q

HOW CAN YOU TELL, WHICH HALF CELL IS UNDERGOING REDUCTION, AND WHICH HALF CELL IS UNDERGOING OXIDATION?

A

WEHN WE CONNECT TWO,2, HALF CELLS TOGETHER, WE ALWAYS HAVE ONE UNDERGOING REDUCTION, AND ONE UNDERGOING OXIDATION.

TO WORK OUT WHICH IS BEING REDUCED AND WHICH IS BEING OXIDISED, WE NEED TO LOOK AT THEIR ELECTRODE POTENTIAL VALUE, E THETA.

ACRONYM,
NO PROBLEM.

THE MOST NEGATIVE HALF CELL, WILL UNDERGO OXIDATION.
THE MOST POSITVE HALF CELL, WILL UNDERGO REDUCTION.

THE REACTION DOES IN FACT HAVE TO REPERESENT THIS ACCORDINGLY.

28
Q

WHY DO WE USE THE STANDARD HYDROGEN ELECTRODE, SHE?

A

ELECTRODE POTENTIALS OF HALF CELLS CAN NOT BE MEASURED ON THEIR OWN.
WE CAN MEASURE THEM AGAINST A REFERNCE HALF CELL, CALLED A STANDARD HYDROGEN CELL, SHE.

THE SHE, HAS AN ELECTRODE POTENTIAL, E THETA, WHICH EQUALS, 0.00V, VOLTS.

29
Q

THE STANDARD HYDROGEN ELECTRODE, USE AND CONDITIONS.

A

THE HYDROGEN, H2, GAS GOES IN AT 298K, KELVINS, AND 100KPa.

WE WILL HAVE A CONCENTRATION OF ONE MOLE, 1moldm^-3, OF H^+ IONS, IN THE BOTTOM OF THE FLASK.

WE HAVE TO USE STANDARD CONDITION OF, TEMPERATURE, PRESSURE, AND THE CONCENTRATION OF IONS.

ASSUMING THAT THESE CONDITION HAVE BEEN MET, THE VOLTMETER SHOULD TELLS US THE STANDARD ELECTRODE POTENTIAL.

30
Q

SHE, STANDARD CONDITION CONCENTRATION.

A

IT IS IMPORTANT TO NOTE, THAT THERE SOME ACIDS ARE MONOBASIC, AND OTHERS ARE DIABASIC.
WE ONLY NEED ONE MOLE, OF THE HYDROGEN, H+, ION.

HCL,
ONE MOLE OF THIS, AS IT IS MONOBASIC.
H2SO4,
HALF A MOLE OF THIS, AS IT IS DIABASIC.

31
Q

THE ELECTROCHEMICAL SERIES.

A

THE ELECTROCHEMICAL SERIES, IS A LIST OF HALF CELL REACTIONS AND THEIR STANDARD ELECTRODE POTENTIALS, E THETA.

THEY WILL ALL BE WRITTEN IN THE REDUCED FORM, SO GAINING ELECTRONS.

AGENTS ON THE LEFT HAND SIDE, OF THE REACTION ARE MORE EASILY REDUCED.

THEY HAVE AN INCREASNG TENDENCY TO GAIN ELECTRONS, MORE POWERFUL OXIDISING AGENT.

AGENTS ON THE RIGHT HAND SIZE OF THE EQUATION, ARE MORE EASILT OXIDISED.

THEY HAVE AN INCREASING TENDENCY TO LOOSE ELECTRON, MORE POWERFUL REDUCING AGENT.

32
Q

CALCULATING STANDARD CELL POTENTIAL.

A

STNADARD ELECTRODE POTENTIALS, E THETA, CAN BE USED TO CALCULATE THE STANDARD CELL POTENTIAL, E THEAT CELL.

E CELL.= E REDUCED- E OXIDISED.

33
Q

WHAT AFFETS STANDARD CELL POTENTIAL?

A

ELECTRODE POTENTIALS, CAN CHANGE IF THE CONDITIONS, DEVIATE AWAY FROM THE STANDARD CONDITIONS.

ELECTRODE POTENTIALS INVOLVE REVERSIBLE REACTIONS.
LIKE ANY OTHER REVERSIBLE REACTION, THE EQUILIBRIUM POSITION CHANGES DEPENDING ON REACTION CONDITIONS.

IF WE CHANGE THE EQUILIBRIUM POSITION, THE CELL POTENTIAL VALUE CHANGES TOO.

34
Q

FACTORS, THAT CAN AFFECT THE STANDARD CELL POTENTIAL.

A

TEMPERAURE.
CONCENTRATION.
PRESSURE.

35
Q

WHAT HAPPENS IF WE CHANGE THE EQUILIBRIUM POSITION?

A

IF WE CHANGE THE EQUILIBRIUM POSITION, THE CELL POTENTIAL VALUE CHANGES TOO.

36
Q

CELL NOTATIONS, WHY DO WE USE THEM?

A

CELL NOTATIONS ARE USED TO SIMPLIFY HOW WE DRAW THE SET UP OF A CELL.
THEY ARE THE STANDARD WAY OF REPRESENTING CELLS IN CHEMISTRY.

37
Q

CELL NOTATION, THE ORDER.

A

AS STANDARD, THEY ARE REPRESENTED LIKE THIS.
THE MOST NEGATIVE HALF CELL POTENTIAL GOES TO THE LEFT OF THE DOUBLE LINE.

REDUCED FORM | OXIDISED FORM || OXIDISED FORM | REDUCED FORM.

38
Q

SINGLE LINES.

A

SOLID SINLGE LINES, SHOW A PHYSICAL STATE CHANGE.

39
Q

DOUBLE LINES.

A

SOLID DOUBLE LINES, SHOW A SALT BRIDGE.

40
Q

CELL NOTATION, TWO,2, AQEOUS IONS.

A

THE TWO,2, AQEOUS IONS, WILL IN FACT BE SEPARATED WITH A COMMA, AND NOT A LINE.
THIS IS BECAUSE THEY ARE IN THE SAME PHYSICAL STATE.

ALSO A SOLID SINGLE LINE, BETWEEN THE LAST ION, AND THE PLATNIUM, Pt, ELECTRODE, AS THERE IS A STATE CHANGE.

41
Q

STANDARD ELECTRODE POTENTIALS, PREDICTION.

A

STANDARD ELECTRODE POTENTIAL, E THETA, CAN BE USED TO PREDICT IF A STATED REACTION IS LIKELY TO PROCEED UNDER STANDARD CONDITIONS.

STEP ONE,1,
IDENTIFY WHICH IS BEING OXIDISED.
THE MOST NEGATIVE ELECTRODE POTENTIAL, E THETA.

STEP TWO,2,
TAKE THAT OXIDISED EQUATION AND REVERSE.
TO SHOW THAT IT IS BEING OXIDISED,
SO LOOSING ELECTRONS.

WRITE THE TWO,2, EQUATIONS TOGETHER.
THE OXIDSED AND THE REDUCED EQUATIONS.
COMBINE THEESE TWO,2, EQUATIONS.
THIS EQAUTION IS THE FEASIBLE REACTION.

DO NOT INCLUDE THE ELECTRONS, IN THIS EQUATION.

CONFIRM BY CALCULATING THE ELECTRODE POTENTIAL, E THETA.

E THETA.= REDUCED- OXIDISED.
ALL FEASIBLE REACTIONS WILL HAVE A POSITIVE ELECTRODE POTENTIAL, E THETA.
MEASURED IN VOLTS,V.

42
Q

STRANDARD ELECTRODE POTENTIAL, PREDICTION DISPROPORTIONATION REACTION.

A

STANDARD ELECTRODE POTENTIAL, E THETA, CAN BE USED TO PREDICT IF A DISPROPORTIONATION REACTION, IS LIKELY TO PROCEED TOO.

ALL FEASIBLE REACTIONS, WILL HAVE A POSITIVE ELECTRODE POTENTIAL, E THETA, VALUE.
MEASURED IN VOLTS, V.

43
Q

PREDICTION, WARNING.

A

JUST BECAUSE WE CALCULATE THE ELECTRODE POTENTIAL, E THETA, TO STATE A FEASIBLE REACTION, DOES NOT NECESSARILY MEAN IT WILL GO.

NON STANDARD CONDITIONS.
IF WE CHANGE THE CONCENTRATION OR TEMPERATURE, THIS CAN CAUSE THE ELECTRODE POTENTIAL TO CHANGE.

THE REDUCTION REACTION.

INCREASING CONCENTRATION, EQUILIBRIUM WILL SHIFT TO THE RIGHT, EASIER FOR THE ELEMENT TO GAIN ELECTRONS.
THIS ELECTRODE POTENTIAL, FOR THIS HALF CELL WILL BECOME MORE POSITIVE, AND THE CELL POTENTIAL WILL BE HIGHER.

THE OXIDATION REACTION.
INCREASING CONCENTRATION.
EQUILIBRIUM WILL SHIFT TO THE LEFT.
LESS ELECTRON WILL BE USED UP.
THE ELECTRODE POTENTIAL OF THE ELEMENT, WILL BECOME LESS NEGATIVE, AND THE FULL CELL POTENTIAL WILL BE LOWER.

KINETICS NOT FAVOURABLE.
THE RATE OF REACTION, IS SO SLOW THAT THERE IS NO REACTION.

IF THE REACTIO HAS A HIGH ACTIVATION ENERGY, IT MAY STOP THE REACTION HAPPENING ALL TOGETHER, UNLESS THIS IS BREACHED.

44
Q

CELL POTENTIAL AND ENTROPY.

A

THE LARGER THE CELL POTENTIAL, THE LARGER THE TOTAL ENTROPY DURING THE CELL REACTION.

ELECTRODE POTENTIAL, E THETA, IS DIRECTLY PROPORTIONAL, TO THE TOAL ENTROPY CHNAGE.

AS ENTROPY AND EQUILIBRIUM CONSTANTS,K, ARE LINKED, WE CAN ALSO SAY THAT ELECTRODE POTENTIAL, E THETA, IS DIRECTLY PROPORTIONAL TO THE NATURAL LOG OF THE EQUILIBRIUM CONSTANK, lnK.

45
Q

THE HALF EQUATION AT EACH ELECTRODE.

A

THE NEGATIVE ELECTRODE, THE ONE BEING OXIDISED, SO LOOSING ELECTRONS.

THE POSITIVE ELECTRODE, THE ONE BEING REDUCED, SO GAINING ELECTRONS.

46
Q

RECHARGABLE BATTERIES.

A

RECHARGABLE BATTERIES, WORK BY SIMPLY PLUGGING THEM IN TO SUPPLY A CURRENT.
THIS CURRENT FORCES ELECTRONS TO FLOW IN THE OPPOSITE WAY.
ALL WE DO REVERSE THE OVERALL DISCHARGE EQUATION, TO SHOW A BATTERY RECHARGING.

47
Q

HOW IS ELECTRICITY GENERATED, IN FUEL CELLS?

A

ELECTRICITY IS GENERATED BY A CONTINOUS EXTERNAL SUPPLY OF CHEMICALS, RATHER THAN A ‘READY STORE” LIKE IN BATTERIES.

48
Q

AN ALKALINE HYDROGEN-OXYGEN FUEL CELL.

A

AN ALKALINE HYDROGEN-OXYGEN FUEL CELL IS ONE EXAMPLE OF A FUEL CELL.

ONE,1,
HYDROGEN FEED.
HYDROGEN IS FED HERE.
IT REACTS WITH OH- IONS, IN SOLUTION IN NINE, 9.
THE REACTION THAT OCCURS IS,

2H2 (aq) + 4OH- (aq) -> 4H2O (l) + 4e-.

TWO,2,
FLOW OF ELECTRONS.
ELECTRONS PRODUCED IN REACTION ONE,1, TRAVEL THROUGH A PLATNIUM ELECTRODE.
PLATNIUM IS A GOOD CONDUCTOR OF ELECTRICITY, BUT IS INERT.

THREE,3,
COMPONENT.
THE FLOW OF ELECTRRONS IS USED TO POWER SOMETHING.
SUCH AS A CAR.

FOUR,4,
OXYGEN FEED.
OXYGEN IS FED HERE.
IT REACS WITH WATER, H2O, AND THE FOUR,4, ELECTRONS MADE FROM STEP ONE,1, TO MAKE OH- IONS.
THRE REACTION THAT OCCURS IS,
O2 (g) + 2H2O (l) + 4e- -> 4OH- (aq).

FIVE,5,
NEGATIVE ELECTRODE, ANODE.
ELECTRON FLOW TO THE NEGATIVE ECTRODE WHICH IS MADE FROM PLATNIUM.

SIX,6,
ELECTROLYTE.
THE ELECTROLYTE IS MADE FROM KOH, POTASSOIUM HYDROXIDE, SOLUTIPN.
IT CARRIES, OH- IONS FROM THE ANODE TO THE CATHODE.

SEVEN,7,
POSITIVE ELECTRODE, CATHODE.
ELECTRONS FLOW FROM THE POSITIVE ELECTRODE, WHICH IS MADE FROM PLATNIUM.
ELECTRONS FLOW FROM THE POSITIVE.

EIGHT,8,
WATER, H2O EMITTED.
THE PRODUCT OF THE REACTION IN STEP ONE,1, IS RELEASED TO THE SURROUNDINGS.

NINE,9,
MOVEMENT OF OH- IONS.
OH- IONS PRODUCED FROM REACTIO FOUR,4, ARE CARRIED TOWARD THE CATHODE VIA THE ELECTROLYTE.

49
Q

ION EXCHANGE MEMBRANES.

A

THESE LINE THE PLATNIUM ELECTRODES, AND THESE ALLOW THE OH- IONS TO PASS THROUGH, BUT NOT HYDROGEN GAS AND OXYGEN GAS.

50
Q

OTHER TYPES OF FUEL CELLS.

A

SOME FUEL CELLS, USE HYDROGEN RICH MOLECULES, SUCH AS METHANOL AND ETHANOL.

51
Q

ALCOHOL FUEL CELLS.

A

THE CAR INDIUSTRY, DEVELOPED ALCOHOL FUEL CELLS, WHICH CREATE HYDROGEN GAS, USING A REFORMER.
THE MAIN ALCOHOLS USED ARE,
METHANOL,
AND ETHANOL.

52
Q

NEWER FUEL CELLS.

A

SOME NEWER FUEL CELLS, NOW THE FUEL DIRECTLY, WITHOUT THE NEED TO CONVERT TO HYDROGEN FIRST.

THIS IS HOW IT WORKS:
THE ALCOHOL IS OXIDISED AT THE ANODE, WITH WATER PRESENT.

CH3OH + H20 -> CO2 + 6e- + 6H+.

THE H+ IONS, PASS THROUGH THE ELECTROLYTE AND ARE OXIDISED, TO WATER.

6H+ + 6e- + 1.5O2 -> 3H2O.

53
Q

WHAT DOES A PLATNIUM, Pt, ELECTRODE PROVIDE?

A

A, SOLID, CONDUCTING SURFACE FOR ELECTRON TRANSFER.

54
Q

ELECTRODE AND ELECTROLYTE HYDROGEN FUEL CELL.

A

ELECTRODE, PLATNIUM.

ELECTROLYTE, POTASSIUM HYDROXIDE SOLUTION.

Chemistry-Organic Chemistry. (18 decks)

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