1.7 Redox reactions

Question 1

In a reaction of 2Cu with O₂ to form 2CuO what are the roles of each reactant in terms of electrons?

Answer 1

Cu - oxidised, reduction agent

O - reduced, oxidation agent

Question 2

If an ions does not change oxidation states then what is it called?

Answer 2

The spectator ion

Question 3

What are the oxidation states of hydrogen?

Answer 3

+1 almost all the time e.g HCl

-1 in metal hydrides e.g NaH

Question 4

What is the oxidation state of group 1 metals?

Answer 4

Always +1 e.g NaCl

Question 5

What is the oxidation state of group 2 metals?

Answer 5

Always +2 e.g MgO

Question 6

What is the oxidation state of aluminium?

Answer 6

Always +3 e.g AlCl₃

Question 7

What are the oxidation states of oxygen?

Answer 7

-2 most of the time e.g MgO
-1 in peroxides e.g H₂O₂
+2 with fluorine - OF₂

Question 8

What is the oxidation state of fluorine?

Answer 8

Always -1

Question 9

What are the oxidation states of chlorine, bromine and iodine?

Answer 9

-1 most of the time

Various + values in coumpounds with oxygen and fluorine

Question 10

What is potassium super oxide?

Answer 10

KO₂ where the potassium makes a ionic bond with an O₂ molecule which forms a rare, coloured powder.

Question 11

What is disproportionation?

Answer 11

Where the same element in a reaction is simaltaniously oxidised and reduced meaning it has 2 oxidation states in the same reaction.