Qualification > Sciences

CHEM PAPER 3 PLEASEEE HELPPP

(1/3) > >>

Mia:
Does anybody have notes or can explain reversible reactions and redox - oxidation and reduction [extended section] ? PLEASE... i rlly need ur help.. ?

elemis:
To understand what oxidation is memorise this :

OILRIG = Oxidation Is Loss Reduction Is Gain            In this case I am talking about the Gain and Loss of ELECTRONS.

Oxidation can also mean an INCREASE in the oxidation NUMBER :

Mg + Fe2+ -------> Mg2+ + Fe

In the above case Magnesium DISPLACED the less reactive IRON from its SALT. IRON gained ELECTRONS to form IRON ATOMS. It was REDUCED.

However, Look at Iron's oxidation numbers. It went from 2+ to 0. IT REDUCED, thus this confirms REDUCTION OCCURED.

Apply this to Mangesium and you should determine that it was OXIDISED.

Mia:
Thank you soo much :)

~$VJ DJ$~:
What is, and what are the diffrences between sacrifical protection and cathodic protection????

help me please

bored2death:

--- Quote from: ~$VJ DJ$~ on June 06, 2010, 12:25:58 pm ---What is, and what are the diffrences between sacrifical protection and cathodic protection????

help me please

--- End quote ---
sacrifical protection is like coating a ship made of steel with zinc. Zinc will "sacrifice" its electrons to the steel which will gain these electrons and become coated. Zinc is more reactive metal and has a greater tendency to lose electrons. get it? or u need more?
cathodic protection is like the electrolysis or electroplating of metals .. like for example a spoon made of silver (crap silver for example|) and you want to protect it from corroding hence u will place it in an electrolysis cell on the cathode electrode and as you know at the cathode reduction occurs which means it also will gain electrons more silver electrons for example and become coated.
I'm sorry if i suck at explaining

Navigation

[0] Message Index

[#] Next page