ELECTROLYTIC PROCESS

                                ELECTROLYSIS

ELECTROLYSIS

PROCESS BY WHICH AN ELECTRIC CURRENT IS PASSED THROUGH A SUBSTANCE TO CAUSE A CHEMICAL CHANGE AND THE CHEMICAL CHANGE IS ONE IN WHICH THE SUBSTANCE LOSES OR GAINS AN ELECTRON.

                                               

THE PROCESS USES AND APPARATUS CONSISTING OF POSITIVE AND NEGATIVE ELECTRODES WHICH ARE SEPARATED FROM EACH OTHER IN A SOLUTION. ELECTRIC CURRENT ENTERS THROUGH THE NEGATIVELY CHARGED ELECTRODE (CATHODE)

POSITIVELY CHARGED PARTS OF THE SOLUTION TRAVEL THE CATHODE, COMBINE WITH THE ELECTRONS AND ARE TRANSFORMED INTO NEUTRAL MOLECULES. THE NEGATIVELY CHARGED PARTS OF THE SOLUTION TRAVEL TO THE POSITIVE ELECTRODE (ANODE), GIVE UP ELECTRONS, AND ARE TRANSFORMED INTO NEUTRAL MOLECULES.

# DIAGRAM OF ELECTROLYSIS

            

# ELECTROLYSIS OF WATER

WATER IS SPLIT WITH ELECTRICITY TO PRODUCE HYDROGEN GAS AND OXYGEN GAS.

                                     

#ELECTROLYSIS OF COPPER

COPPER CHLORIDE IS SPLIT WITH AN ELECTRICAL CURRENT TO PRODUCE COPPER AND CHLORINE GAS. DURING ELECTROLYSIS, COPPER LOSES ELECTRONS, HAS AN OVERALL POSITIVE CHARGE, AND BECOMES A CATION, WHICH IS ATTRACTED TO THE CATHODE OR NEGATIVE ELECTRODE. CHLORINE GAINS ELECTRONS, HAS AN OVERALL NEGATIVE CHARGE AND BECOMES AN ANION, WHICH IS ATTRACTED TO THE ANODE OR POSITIVE ELECTRODE.

                                            

#FARADAY'S FIRST LAW OF ELECTROLYSIS

ACCORDING TO THIS LAW, THE CHEMICAL DEPOSITION DUE TO FLOW OF CURRENT THROUGH AN ELECTROLYTE IS DIRECTLY PROPORTIONAL TO THE QUANTITY OF ELECTRICITY (COULOMBS) PASSES THROUGH IT. i.e MASS OF CHEMICAL DEPOSITION, WHERE Z IS A CONSTANT OF PROPORTIONALITY AND IS KNOWN AS ELECTROCHEMICAL EQUIVALENT OF THE SURFACE.

IF WE PUT Q=1 COULOMBS IN THE ABOVE EQUATION, SO WE GET Z= M WHICH IMPLIES THAT ELECTROCHEMICAL EQUIVALENT IS GENERALLY EXPRESSED IN TERMS OF MILLIGRAM PER COULOMB OR KILOGRAM PER COULOMB.

OR W=Z it

I=CURRENT IN AMPERES

t=TIME IN SECONDS

Z= CONSTANT OF PROPORTIONALLY(ELECTROCHEMICAL EQUIVALENT)

#FRADAY'S SECOND LAW OF ELECTROLYSIS

WHEN THE SAME QUANTITY OF ELECTRICITY IS PASSED THROUGH DIFFERENT ELECTROLYTES THE MASSES OF DIFFERENT IONS LIBERATED AT THE ELECTRODES ARE DIRECTLY PROPORTIONAL TO THEIR CHEMICAL EQUIVALENCE.

#BATTERY TECHNOLOGY

1. LEAD ACID

2. NICKEL-CADMIUM

3. NICKEL-METAL HYDRIDE

4. Li-ion

# LEAD-ACID BATTERIES

LEAD-ACID BATTERIES ARE THE MOST CONVENIENT CHOICE BASED ON COST. THE TECHNOLOGY. LEAD-ACID BATTERIES ARE WORSE THAN OTHER TECHNOLOGIES BASED ON ALL THE OTHER CHARACTERISTICS. DISPOSAL IS ANOTHER IMPORTANT ISSUE.

IN PARTICULAR LEAD-ACID BATTERIES ARE NOT SUITABLE FOR LOAD-FOLLOWING POWER BUFFER APPLICATIONS BECAUSE THEIR LIFE IS SIGNIFICANTLY WHEN THEY ARE DISCHARGED VERY RAPIDLY OR WITH FREQUENT DEEP CYCLES.

#LEAD-ACID BATTERIES LIFE

LEAD-ACID BATTERIES ARE VERY SENSITIVE TO TEMPERATURE EFFECTS. IT CAN BE EXPECTED THAT BATTERY TEMPERATURE EXCEEDING 77°F. DECREASE EXPECTED LIFE BY APPROX 50% FOR THE 18°F. INCREASE IN AVERAGE TEMPERATURE

#LEAD-ACID BATTERIES

AS THE BATTERY DISCHARGE, SULFURIC ACID CONCENTRATION DECREASE. AT THE SAME TIME, LEAD SULFATE IS DEPOSITED ON THE ELECTRODE PLATES. CHARGING FOLLOW THE INVERSE PROCESS, BUT A SMALL PORTION OF THE LEAD SULFATEVREMAINS ON THE ELECTRODE PLATES. ON EVERY CYCLE, SOME MORE LEAD SULFATE DEPOSITS BUILD UPON THE ELECTRODE PLATES, REDUCING THE REACTION AREA AND, HENCE NEGATIVITY AFFECTING THE BATTERY PERFORMANCE.

ELECTRODE PLATES  SULFATTION IS ONE OF THE PRIMARY EFFECTS THAT AFFECTS BATTERY LIFE.

TO AVOID ACCELERATING THE SULFRATION PROCESS, BATTERIES NEED TO BE FULLY CHARGED AFTER EVERY DISCHARGE AND THEY MUST BE KEPT CHARGED AT AFLOAT VOLTAGE HIGHER THAN THE NOMINAL VOLTAGE. FOR LEAD ACID BATTERIES AND DEPENDING THEIR TECHNOLOGY THE FLOAR VOLTAGE IS BETWEEN 2.08 V/CELL AND 2.27 V/CELL. FOR THE SAME REASONS, LEAD-ACID BATTERIES SHOULD NOT BE DISCHARGED BELOW 1.75 V/CELL