electrolysis

dilute sulfuric acid - anode product

oxygen

dilute sulfuric acid - cathode product

hydrogen

dilute sulfuric acid - anode observations

bubbles of oxygen gas

dilute sulfuric acid - cathode observations

bubbles of hydrogen gas

to find products formed in a substance

eg. molten potassium iodide

anode - non metal

cathode - usually metal

anode - iodine

cathode - potassium

Panic mnemonic

Positive is Anode, negative is cathode

electrolysis

when an electric current is directed through a molten or aqueous ionic compound resulting in the compound decomposing or breaking down

electrolyte

the ionic compound in a molten or dissolved solution that can conduct electricity

electrode

the rod used to direct energy

inert so they’re made of platinum (metal) or carbon/graphite (non - metal) so there aren’t any side reactions

why ionic compounds need to be molten or aqueous

mobile ions (solid ionic compounds don’t have free ions to move or carry charge)

why a substance needs to be manufactured through electrolysis

takes too high of a temperature to extract the product

molten lead bromide - anode product

bromine gas

molten lead bromide - cathode product

lead metal

molten lead bromide - anode observations

bromine gas is released

molten lead bromide - cathode observations

lead metal is formed

concentrated aqueous sodium chloride - anode product

chlorine

concentrated aqueous sodium chloride - cathode product

hydrogen

concentrated aqueous sodium chloride - anode observations

chlorine gas is produced

concentrated aqueous sodium chloride - cathode observations

bubbles of hydrogen gas

simple electrolytic cell

remember that cathode is connected to the negative side of the battery and anode is connected to the positive side

electroplating anode

nickel, gold, silver

electroplating cathode

steel, copper, plastic

electroplating

uses electrolysis to coat a thing layer of a metal onto the surface of another metal

• inprove appearance and resistance to corrosion

the cathode is the object that needs to be electroplated

the anode is the plating metal

electroplating a strip of iron with tin

• At the anode:

  • Tin atoms lose electrons to form tin ions in solution

  • The loss of electrons is oxidation

• At the cathode:

  • Tin ions gain electrons to form tin atoms

  • The gain of electrons is reduction

  • The tin atoms are deposited on the strip of iron metal, coating it with a layer of tin

halides

compounds formed with halogen elements