3 - redox 1

Question 1

half equations for 2Mg + O2 –> 2MgO

Answer 1

Mg –> Mg2+ + 2e-
O2 + 4e- –> 2O2-
mg has been oxidised and lost electrons
o has been reduced and gained electrons

Question 2

OIL RIG

Answer 2

Oxidation
Is
Loss
Reduction
Is
Gain

Question 3

what is the oxidation number of an uncombined element?

Answer 3

zero

Question 4

what is the sum of the oxidation numbers of all the elements in a neutral compound?

Answer 4

zero

Question 5

what is the sum of the oxidation numbers of all the elements in an ion?

Answer 5

the charge on the ion

Question 6

what is the oxidation number of fluorine?

Answer 6

-1

Question 7

what is the oxidation number of hydrogen?

Answer 7

+1 except when combined with a less electronegative element then it becomes -1

Question 8

what is the oxidation number of oxygen?

Answer 8

-2 except in peroxides it is -1 and when combined with fluorine it is positive

Question 9

what happens to the oxidation number when an element is oxidised?

Answer 9

increases

Question 10

what happens to the oxidation number when an element is reduced?

Answer 10

decreases

Question 11

what is a systematic name?

Answer 11

when an element can have more than one oxidation state written with roman numerals
e.g. iron(II)

Question 12

when should you use a systematic name?

Answer 12

whenever possible

Question 13

reminder to practice….

Answer 13

half equations
adding oxygen, etc.