January 22, 2023
Stoichiometry
In the I/GCSE chemistry curriculum:
- Relative atomic mass - mass of the element (average) for example 12 for Carbon
- Relative molecular mass - adding up of relative atomic mass.
- Mole concept - 6x10(23), formulas include - Moles = Mass/RMM Concentration = Moles/Volume
Electricity and Chemistry
- Electrolysis of Molten Lead Bromide - cathode- lead, anode- bromine gas
- Electrolysis of Concentrated HCl - cathode-hydrogen, anode-chlorine
- Electrolysis of Concentrated NaCl - cathode-hydrogen, anode-Chlorine
- Usually metals and hydrogen are made at the cathode, non-metals are made at the anode. With a molten compound (iron oxide) you will just get iron and oxygen gas. In a solution, the less reactive of the two substances will produce hydrogen not sodium.
- Electroplating - anode has to be made out of the metal you want to electroplate the object with-ions of the same metal as the electrolyte, cathode with the object you want to electroplate.(do not corrode/rust/look prettier)
- Aluminium/copper used for cables-good conductors of heat and electricity/ductile, they are also both cheaper than silver, aluminium cheapest out of the three.
- Plastics/Ceramics - good insulators as they do not conduct electricity.
Chemical Energetics
Some definition in the I/GCSE chemistry curriculum:
- Exothermic - gives out heat and energy/makes bonds
- Endothermic - takes in heat and energy/breaks bonds
- Fuels are burned to produce heat energy such as oil/natural gas to produce an exothermic reaction.
- Fuels - hydrogen.
- U235 used as a source of energy-decays to form energy used to make steam for power plants.
End of this topic!