ES 2

Question 1

what happens to an ion when it looses electrons

Answer 1

oxidation

Question 2

what happens to an atom when it gains electrons

Answer 2

reduction

Question 3

what is a REDOX reaction

Answer 3

when both oxidation and reduction occur in the same reaction

Question 4

features of an oxidising agent

Answer 4

accepts and gains electrons from reducing agent
becomes reduced

Question 5

features of a reducing agent

Answer 5

donates electrons to oxidising agent
becomes oxidised

Question 6

what happens to the oxidation state when an element is oxidised

Answer 6

the oxidation state increases e.g. Cu — Cu2+ + 2e-

Question 7

what happens to the oxidation state when an element is reduced

Answer 7

the oxidation state decreases e.g. 1/2 O2 + 2e- — O2-

Question 8

what is the rule for oxidation states in elements

Answer 8

atoms in an element are in oxidation state zero e.g. Cu, O2, Mg

Question 9

what is the rule for oxidation states in simple ions

Answer 9

the oxidation state is the same as the charge on the ion

Question 10

what is the rule for oxidation states in compounds

Answer 10

zero since compounds have no overall charge (all constituent elements must add up to zero)

Question 11

what is the oxidation state of complex ions

Answer 11

oxidation number of all the constituent ions must add up to the charge on the ion