P4 & 5 Recap

Saturday 12th December 2020

• Starter
• 1. What is the Relative mass for Protons, Electrons and Neutrons
• 2. What is the Relative Charge for Protons, Electrons and Neutrons
• 3. Describe the atom structure

Answers

• 1. The Relative Mass for Proton is 1, Neutron is 1 and Electrons is very small
• 2. The Relative Charge for Proton is +1, Neutron is 0 and Electron is -1
• 3. There is an atom and inside the atom is a nucleus and inside the nucleus there are protons and neutrons. Orbiting the Nucleus is the Electrons

What is Electrolysis?

• 
• Electrolysis means splitting up ionic compounds with electricity.
• An ion is a charged atom but a better way to put it is a loss and gain of electrons.
• The ion with a negative charge is called anion and its attracted to the anode during electrolysis
• The ion with a positive charge is called cation and its attracted to the cathode during electrolysis
• Caption: A diagram of the set up of Electrolysis

Electrodes

• Electrodes are rods that conduct electricity and they are made from Carbon.
• REMEMBER -
• Metals always form at the negative Electrode (Cathode)
• Non - Metals always form at the positive Electrode (Anode)
• What does OIL RIG stand for?

OIL RIG

• OIL RIG stands for Oxidation is Loss and Reduction is Gain
• Oxidation is loss of Electrons and Reduction is gain of Electrons
• Reduction occurs at the Cathode
• Oxidation occurs at the Anode
• https://www.youtube.com/watch?v=NxuvwnRuylU

Electrolysis at Lead bromide

• Lead (Pb2+) will be attracted to the anode
• Bromine (Br-) will be attracted to the cathode

Electrolysis to extract Metals

• Why cant we use Carbon to extract metals?
• Aluminium is more reactive than carbon
• 

Electrolysis at aqueous solutions

• Rules at the anode - The least reactive anion gets discharged
• Rules at the cathode - If the Halide (Group 7) is present it will always get discharged

Half Equations

• Mg2+ + 2e- --> Mg = CATHODE
• Ca2+ + 2e- --> Ca = CATHODE
• 2cl- ---> 2Cl + 2e- = ANODE
• 2Br- ---> 2Br + 2e- = ANODE

Watch video

• https://www.youtube.com/watch?v=AhTRiL6xjBA