Oxidation and reduction Flashcards
Oxidation is what?
The loss of electrons
Reduction is what?
The gain of electrons
What is an oxidising agent?
It is a substance that brings about oxidation in other substances
What is the reducing agent?
It is a substance that brings about reduction in other substances
Is a reducing agent oxidised or reduced?
It is oxidised
What is an oxidation number?
It is the charge that an atom has or appears to have one electrons are distributed according to certain rules
What oxidation number does uncombined elements have?
Zero
What oxidation number does an ion have?
The same as its charge
What oxidation number does the compound have?
In a compound, the oxidation numbers must add up to 0
What oxidation number will oxygen have if it is not in a peroxide or in the compound? OF?
Minus two
What oxidation number does oxygen have if it is bonded in a peroxide?
It will have minus one
E.g. H2O2 oxygen will have the oxidation number of minus one
Why does oxygen have an oxidation number of +2 in the compound? OF?
As fluorine is more electronegative than oxygen therefore fluorine gets the negative charge
What oxidation number does hydrogen have if it’s not in a metal hydride?
Plus one
What are metal hydrides
They are when hydrogen is bonded to a metal
E.g. in sodium hydrogen will be given the oxidation number minus one as it bonded to a mental hydride
What oxidation number does the halogens usually have if they are not bonded to a more electronegative atom?
Minus one
E.g. chlorine will have the oxidation number minus one unless it is bonded to fluorine which would give it a plus one charge as fluorine is more electronegative
In a ion complex, the oxidation numbers must equal what?
The charge of the ion so the whole complex ion
If an element is oxidised does its oxidation number increase or decrease?
Increase
If an element is reduced, does its oxidation number increase or decrease?
Decrease
What is the electrochemical series?
It is a list of elements in order of their ability to be oxidised
In the electrochemical series metals at the top or what?
The most reactive so are easily oxidised so have a high tendency to lose electrons
In the electrochemical series metals at the bottom or what?
They are the least reactive and resist oxidation so they do not lose electrons easily
What is the electrochemical series used for for?
Predicting the results of displacement reactions
Will a more reactive metal in the electrochemical series displayed a metal below it
Yes
What is the use of the electrochemical series?
It can predict the behaviour of elements and redox reactions as higher elements will displace lower elements
