2.1.5 Redox

Question 1

What is the oxidation state of any pure element?

Answer 1

0

Question 2

What is the oxidation state for oxygen?

Answer 2

-2

Question 3

What is the exception for the oxidation state of oxygen?

Answer 3

in peroxides oxygen= -1

Question 4

What is the oxidation state for hydrogen?

Answer 4

+1

Question 5

What is the exception for the oxidation state of hydrogen?

Answer 5

in metal hydrides hydrogen= +1

Question 6

What are the oxidation rules for ions?

Answer 6

in a simple ion e.g. Mg the oxidation state= the charge of ion
in a molecular ion e.g. CH4 the sum of oxidation states must= overall charge of ion

Question 7

What are the oxidation rules for compounds?

Answer 7

sum of the oxidation states must= 0

Question 8

What is an oxidising agent?

Answer 8

something which accepts electrons and gets reduced

Question 9

What is a reducing agent?

Answer 9

something that donates electrons and gets oxidised

Question 10

What does an increase in oxidation state show?

Answer 10

element has lost electrons and been oxidised

Question 11

What does a decrease in oxidation state show?

Answer 11

element had gained electrons and been reduced

Question 12

What is a peroxide?

Answer 12

something that has two oxygen atoms bonded together e.g. H2O2

Question 13

What is a metal hydride?

Answer 13

transition metal bonded to hydrogen

Question 14

What is a disproportionation reaction?

Answer 14

a substance is both oxidised and reduced within a reaction