Oxidation/Reduction question (1 Viewer)

[minijumbuk]

Hey, I was just wondering...

In the data sheet, for example, wouldn't the strongest oxidant naturally be the weakest reductant?

 

[flicka08]

yea thats right
just remember the data sheet is the standard reduction potentials so the strongest reductant will be at the very top

 

[Undermyskin]

Or at the bottom. I've got the sheet where Potassium is at the bottom! Just need to look at E and find the smallest number then it's the strongest reductant

 

[minijumbuk]

So if that's what you're saying...

Strongest reducing agent = K+
Strongest oxidising agent = K
Weakest reducing agent = K
Strongest oxidising agent = K+
?

 

[undalay]

So if that's what you're saying...

Strongest reducing agent = K+
Strongest oxidising agent = K
Weakest reducing agent = K
Strongest oxidising agent = K+
?

Reducing agent, undergoes oxidation, oxidation is loss.
K+ isn't going to lose any more electrons (it's gonna be very hard)
Thus its a very very weak reducing agent.

On the standardp potential table:
F2 is the best oxidising agent.
K is the best reducing agent.
K+ is the weakest oxidisnig agent
F- is the weakest reducing agent.

 

[minijumbuk]

So why would F- be a weaker reducing agent than K+?

 

[undalay]

because i said on the table.

There is no equation for oxidation of K+ on the table.
So it cannot be determined, although i would suspect K+ would be weaker in reality.

 

[minijumbuk]

Argh, that's the mistake I did, and I lost the mark in the prac. assessment T_T

 

[Tim035]

You could also remember that oxidation and reduction potential are linked to ionization energy and electron affinity levels.
Ionization levels decrease down the periodic table and increase across, but there are some irregularities if the outer sub shell has a full or exactly half filled electron configuration. Lower ionization levels mean less energy is needed to remove the least tightly bound electron and so the element will more easily oxized.

Electron affinity levels always have negative associated values as the system loses energy for this process to occur. Large negative values occur in atoms towards the top right of the periodic table with exclusion of noble gases. Less negative values occur around the alkaline earths Be, Mg, Ca etc... Large negative values mean the element is more readily going to except an electron thus becomming reduced.



..... Actually on second thought, just learn the order based on that table they give you.

 

[minijumbuk]

You could also remember that oxidation and reduction potential are linked to ionization energy and electron affinity levels.
Ionization levels decrease down the periodic table and increase across, but there are some irregularities if the outer sub shell has a full or exactly half filled electron configuration. Lower ionization levels mean less energy is needed to remove the least tightly bound electron and so the element will more easily oxized.

Electron affinity levels always have negative associated values as the system loses energy for this process to occur. Large negative values occur in atoms towards the top right of the periodic table with exclusion of noble gases. Less negative values occur around the alkaline earths Be, Mg, Ca etc... Large negative values mean the element is more readily going to except an electron thus becomming reduced.



..... Actually on second thought, just learn the order based on that table they give you.

The table they gave me was a table with radicals, hence I could not use ionisation energy, nor electronegativity.

 

[Tim035]

The table they gave me was a table with radicals, hence I could not use ionisation energy, nor electronegativity.

Radicals still follow the normal rules of oxidation potential as a matter of fact the rules stand stronger in the sense that ionization levels will increase in a linear fashion until the element reaches a noble gas configuration at which point an expodential jump will occur. I was trying to increase your understanding whilst confirming your own beliefs- Think about it, if an element has a high ioniziation potential it is going to have a low electron affinity level and vice versa;

Just learn it in terms of the standard potentials sheet they give you kid...

 

[minijumbuk]

Extra-curricular knowledge is cool though =(