Question

REDOX question. I can not get this straight,
Which is the [red] and which is the [ox]?
SO4(2-) or SO3(2-)? Please explain as well. thx!

Answer 1

LEO the lion says GRR

Lose electrons oxidation

Gain electrons reduction

So,
the oxidizing agent is reduced
the reducing agent is oxidized


When negative charge goes up that means that the number of electrons the atom or molecule has, has increased

When positive charge goes up that means the number electrons the atom or molecule has, has decreased

When the molecule/element is neutral it means that the number of protons equal the number of electrons.

When looking at individual atoms for their oxidation state we simply follow two rules:
1. Oxidation state is the charge atoms would have if every bond was a 100% ionic.
2. Which ever is more electronegative gets the electrons

so with SO4

each oxygen will have a -2 charge because it is more electronegative than sulphur and with -2 charge it obeys the octet rule (look up periodic table trend electronegativity on google images)

so, -2*4 = -8
since the entire compound has a charge of -2, we can set up a simple equation to figure out sulphurs oxiation state

-2 = x + (-8)
where,
x = the oxidation state of sulphur.
Therefore Sulphur has an oxidation state of +6

Now look at SO3

same deal this time

-2*3 = -6

Set up the equation
-2 = x + (-6)
therefore the oxidation state of the sulphur is
+4

Now just read what I wrote above to see which one was reduced and which was oxidized

Answer 2

Sorry for the really long answer I just wanted to be thorough.

Answer 3

You may be answering this, but could this be correct?

if equn is
SO4(2-) + 2H+ +2e = SO3(2-) +H2O

is that like saying

Ox+ne = Red?

and therefore the sulfate ion would be the "ox"?

Answer 4

Just read what I wrote and memorize the few things if you want to do well on your test

Answer 5

What if Im not given that data?

Answer 6

I think from what you've said, that sulfate has been oxidized to sulfite. Please tell me if that's right.

Answer 7

well you will be given a periodic table right?

Answer 8

electronegativity trend is pretty easy to remember

Answer 9

No, we won't be given one. or a table of half cell reactions

Answer 10

Can you just tell me if what i am thinking based off what you said is right?

Answer 11

I'm saying that sulfate is the species oxidized.

Answer 12

were you required to memorize the first few rows of elements?

Answer 13

Actually you can just guess which is which by looking at it without doing the calculations

Answer 14

also, when you say which one is more electronegative, that trips me up because sulfate and sulfite are made up of the same elements

Answer 15

http://chemwiki.ucdavis.edu/ @api/deki/files/1190/Electronegativity_Trend_IK.png?size=bestfit&width=650&height=350&revision=1

Answer 16

electronegativity is the affinity an element has for an electron

Answer 17

Oxygen I believe is more electronegative. so there is more tendency to accept where there is more oxygen. Yes?

Answer 18

or does it mean there is more to give away, analogous to having more "money" so you can donate...

Answer 19

This better exemplifies the trend,

http://www.chem.umass.edu/~whelan/genchem/whelan/class_images/111_Electronegativity_Table.jpg

Sulphur has less electronegativity than oxygen, that means electrons are going to hang around oxygen more than they will sulphur

See my leo the lion says Grr thing to figure out which compound is oxidized and which is reduced

Answer 20

electronegativity is fundamentally important in chemistry it explains bonding

Answer 21

Sort of kind of

Answer 22

so can I assume you will not tell me if I'm right? That sulfate is oxidized species?

Answer 23

I can check one second

Answer 24

AHA! So you are not sure either. funny.

Answer 25

Oxidation state increases means loss of electrons means SO4 is oxidized relative to SO3 which is reduced because it decreases in oxidation state

Answer 26

Just look at LEO the lion says GER and knowing that SO4 has a higher oxidation state than SO3 you should be able to figure out the answer for yourself

Answer 27

Now I'm going to go back to studying because you are not a very appreciative person

Answer 28

So SO3 is oxidized to SO4, thus SO3 is the reducing agent
SO4 is reduced to SO3, thus SO4 is the oxidizing agent

Answer 29

I hope you can follow what I wrote, I'm simply out of practice with these types of questions and also I have 4 exams to write this week so my brain is a little distracted. Also it is pretty offensive that when I just gave you all the information you think that I cannot answer it. I'm doing you a favour and you are antagonizing me. Anyways this is the last time I help you.

Answer 30

You could have saved me time and said you don't know for sure.

Answer 31

ugh I do know for sure I just gave you all the rules to figure it out yourself then I told you the answer.

Answer 32

The fact that you think I dont know what I'm talking about is actually pretty funny. Anyways I'm done wasting my time with you