1. E_chem -> E_electr. Some chemical reactions can generate electricity. 
2. E_electric -> E_chem. Electricity can also cause a chemical reaction to happen that would not occur spontaneously. 

• This is the setup for a Galvanic cell. 
• It converts chemical energy into electrical energy. 

• We call it a GALVANIC CELL 
• It is also called a VOLTAIC CELL 

• The electrode potential of the hydrogen electrode at 25℃ is estimated to be 4,4 V. 
• However, in order to use this as a reference electrode this value is set to zero at all temperatures so that it can be compared with other electrodes

• INCREASING THE RATE OF THE FORWARD REACTION, WHICH RELEASES MORE ELECTRONS AT THE ANODE AND ACCEPTED AT THE CATHODE.

• increasing the surface area (size) of the electrodes

• increasing the diameter of the salt bridge and decreasing its length  (making it wider and shorter)

• increasing the concentration of the salt solution in the salt bridge. 

The EMF (cell Voltage) is increased by:

Increasing the concentration of REACTANTS.
Decreasing the concentration of PRODUCTS.
This favours the forward reaction, which transfers more electrical energy in the form of more electrons moving from anode to cathode.
HOWEVER - EMF IS NOT AFFECTED BY:
* Increased electrode surface area 
* Wider, shorter, more conductive salt bridge             * Because those changes do not change the    
  concentration of species in solution.
* Therefore, it does not affect the equilibrium               
  position to favour either fwd or reverse 
  reaction in the net ionic reaction.

• At the negative electrode, the least reactive species (from the possible cations in solution) will be reduced into atoms from ions.

• Because hydrogen is less reactive than sodium, the hydrogen is discharged as H atoms that then bind to form H₂-molecules.

• The anode is generally composed of the material that we want to deposit. 
• E.g. Copper in the case of copper plating, nickel in the case of nickel plating.
• It is also possible to plate using “inert” anodes like carbon rods in certain cases. 

• The cathode is the component on which we intend to deposit the metal. 
• In a plating workshop this is commonly referred to as the “work-piece”.

• He showed that the amount of metal deposited at the cathode and the amount dissolved at the anode are directly proportional to the quantity of electricity passed, in other words, to the current and time period of the electro-deposition. 
• Thanks to Faraday's efforts and Faraday's Constant (F = 96 500 C), we can calculate the deposit mass of any metal that we are plating based on its atomic mass and the number of electrons involved in the electrochemical reaction. The formula use is:
• n = q/F  (where n=number of moles of e^- transferred between electrodes, q=charge, F=96500 C)

• So, to electroplate a medal with Copper, do not use copper(II) nitrate as electrolyte. 
• Use CuSO₄ (aq)

• YES!
• We call this QUANTITATIVE ELECTROCHEM.

• Q = It
• n = q/F
• m = n.Mr
  
  See below:

• the mercury cell
• the diaphragm cell
• the membrane cell

• Chlorine
• Hydrogen gas 
• Sodium hydroxide (caustic soda)

• chlorine gas
• hydrogen gas
• sodium hydroxide (caustic soda)

• Why do you think brine can conduct electricity?

• negative value = DIFFICULT to be reduced.
• the other element or compound has a greater tendency to REDUCED.

• positive value = EASY to be reduced.
• The other element or compound has a greater tendency to be OXIDISED.

• The negative electrode should be the object to be electroplated.
• The positive electrode should be the metal that you want to coat the object with.
• The electrolyte should be a solution of the coating metal, such as its metal nitrate or sulfate.

In an electrolytic cell, an external power source drives a non-spontaneous chemical reaction. Here, the anode is the positive electrode, and the cathode is the negative electrode.

• Anode: Positive electrode where oxidation occurs. It attracts anions (negative ions) from the electrolyte because opposite charges attract.

• Cathode: Negative electrode where reduction occurs. It attracts cations (positive ions).

Voltaic (Galvanic) Cells:

In a voltaic or galvanic cell, a spontaneous redox reaction generates an electric current. Here, the roles of the anode and cathode are determined by the direction of the spontaneous chemical reaction.

• Anode: Negative electrode where oxidation occurs. In a galvanic cell, it is negative because it releases electrons into the external circuit. Anions in the electrolyte do not move towards the anode in this case. Instead, the movement of ions in the electrolyte is more about maintaining electrical neutrality rather than being attracted to the electrodes.

• Cathode: Positive electrode where reduction occurs. It attracts cations from the electrolyte.

Key Differences:

• Electrode Charge: In an electrolytic cell, the anode is positive and attracts anions, while in a galvanic cell, the anode is negative.

• Direction of Current: In an electrolytic cell, the current is driven by an external power source, whereas in a galvanic cell, the current is generated by the chemical reaction.

In summary, in a galvanic cell, the anode does not attract anions because it is negatively charged, and the movement of ions is primarily driven by the need to balance charge during the redox reaction, rather than attraction to the electrodes.