Question

Oxidation States tutorial

Answer 1

@This_Is_Batman

Answer 2

Okay so lets get started
First of all lets understand what are/or what these oxidation states show
- basically saying all they show is 'how many electrons this particular element or compound- is able to give/take or already gave/took'

Answer 3

So now we move one to periodic table
these are maximum oxidation states each group can reach

Group : 1
Oxidation state : +1 (loose 1 electron)

Group : 2
Oxidation state : +2 (loose 2 electrons)

Group : 3
Oxidation state : +3 (loose 3 electrons)

Group : 4
Oxidation state : +4 (loose 4 electrons)

Group : 5
Oxidation state : -3 (gain 3 electrons)

Group : 6
Oxidation state : -2 (gain 2 electrons)

Group : 7
Oxidation state : -1 (gain 1 electron)

Group : 8
Oxidation state : 0 (neither gain nor loose any electron)

Answer 4

now i'll explain reasoning

Answer 5

Usually each element always want to reach its 'full noble state' i'd say
meaning have filled last shell and thus have electronic configuration which is same as of one of the noble gases

Answer 6

So
Group 1 : has 1 electron in its last shell
to get to its 'noble' state, group 1 has to gain 7 more electrons
BUT it also can loose that 1 electron in the last shell and reach the noble state

imagine it this way, you are going to the mall lets say and you know about 2 ways to get there, meaning 2 routes
one longer
one shorter
which one you'd want to use more?
shorter right? :)

same thing happens here
for group 1 its easier to Loose that 1 electron rather than gain 7 more electrons
thus maximum oxidation state of group 1 elements is always +1

Answer 7

same concept can be applied to Group 2 and 3

Answer 8

for group 4 as well

Answer 9

now as we move to group 5-7
this one is a bit different though we can use same idea

now why do group 5-7 gain rather then loose electrons?
well look
lets say group 7
element of group 7 has 7 electrons in its last shell
to reach 'noble state' it can loose all 7 electrons OR gain 1 more electron

which one is more convenient?
gain 1 more electron right?
so that is why group 7 usually gain 1 electron rather then loosing 7 electrons

Answer 10

thats why their maximum oxidation state is -1

Answer 11

same concept is applied to group 5 and 6

Answer 12

now
next there are some oxidation states you have to always remember
these elements have 'fixed' oxidation state that is ALWAYS same

H : +1
O : -2
F : -1
OH : -1
and group 1 and 2 are included

group 1 and 2 (maybe 3 also) and 7 have fixed oxidation states
other groups tend to have different oxidation states depending on a compound

Answer 13

Well thats pretty much it about higher oxidation states :)

Answer 14

next we will move on to Oxidation states in Pure element and in Compounds

Answer 15

Always Always remember pure element has oxidation state of 0
because it neither lost or gained any electron (not involved in reaction yet)

Answer 16

for example if in reaction you are given
Al + Cl2 --->
both Al as well as Cl2 have oxidation states of 0

Answer 17

same goes to Compounds actually
meaning if you are given a compound
lets say HCl
its SUM of oxidation states has to ALWAYS be equal to 0

Answer 18

this idea is true when you are not given anything like this

Answer 19

or