Redox reactions Flashcards
Rules 1 2 and 3
1- any element in their natural state eg O2 has an oxidation number of 0
2- any molecule eg CO2 has an oxidation number of 0, because all oxidation numbers of each element in the molecule add up to 0
3- the oxidation numbers of elements in an ion have an oxidation number that add up to the charge of that ion eg CO3 2- has an oxidation number of -2
Rule 4
The oxidation number of any group 1, 2 or 3 element is that of the group they are in
Eg potassium is +1 and Mg is 2+
Rule 5
Fluorine has oxidation number of -1
rule 6
hydrogen usually has oxidation number of +1
rule 7
Oxygen usually has oxidation number of -2
rule 8
Chlorine usually has oxidation number of -1
What is the reducing agent in a reaction??
The chemical that is oxidised (looses electrons)
What is the oxidising agent in a reaction??
The atom that’s reduced ( gains electrons)
Which element in group one is the best reducing agent and why??
Francium- easiest to lose its outer electron due to largest atomic radius
Which group 7 element is the best oxidising agent??
Fluorine- easiest to gain electron as the outer shell is closest to the positive nucleus
What is the name of a reaction where an element like Cl2 gas becomes two ions with a +1 and -1 oxidation number in two different molecules
In a reaction, you might have Cl2 gas which splits to be involved in two products, one with an oxidation number of +1 and one is -1
This is a disproportionation reaction
What do the Roman numerals in an elements name stand for? Eg V or II??
The Roman numeral indicates the oxidation number of the element it is to the right of
Chlorate (I) and chlorate (II) oxidation number and formula??
What do all 4 chlorate ions have in common
Chlorate (I)= ClO- and the cl has an oxidation state of +1
Chlorate (III)= ClO2- and the oxidation state of Cl is +3
All of them have a 1- charge
Oxidation and formula of chlorate (V) and (VII)
Chlorate (V)= +5 and a formula of ClO3-
Chlorate (VII)= +7 and a formula of ClO4-
