Cation or anion?

[bluefish9810]

This is probably a stupid question, but how do you know when someone is a cation or anion?

Ok, so for example CH3-CHO-Cl

If Cl is abstracted by an strong electrophile, it would become CH3-CHO, would this be a cation because it lost a "negative" charge Cl?

And if, hypothetically, the alpha hydrogen is abstracted, it would be CH2-CHO-Cl, but would it then become an anion because it lost a proton (H+)?

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[altogether]

cation = positively charged ion
anion = negatively charged ion

 

[tartrate]

This is probably a stupid question, but how do you know when someone is a cation or anion?

I lol'd

"Oh, he's such a cation..."

 

[BrianK0220]

http://en.wikipedia.org/wiki/Main_Page

 

[OBEAHDOCTOR]

i lol'd

"oh, he's such a cation..."

lmao

 

[bluefish9810]

cation = positively charged ion
anion = negatively charged ion

Yeah I understand that but how do you know when something creates a positively charge ion or a negatively charged ion?

so NH4+ is obviously a cation...but what about NH3OH? N is bound to 4 atoms (3H and 1 OH)...so would that still be a cation even though the extra bound molecule is an OH (usually negative charge) instead of an H (usually positive charge) in NH4+?

 

[Rabolisk]

I don't believe NH3OH exists. But the correct way to think about this is to just think about the definition of cation/anion. A cation has an overall positive charge, which means that it has more protons than electrons. You can also only count valence electrons and use the sum of formal charge of each element. But first try counting the number of electrons of NH3OH as you described it, and the number of protons and see what you get.

 

[orgohacks]

This is probably a stupid question, but how do you know when someone is a cation or anion?

Ok, so for example CH3-CHO-Cl

If Cl is abstracted by an strong electrophile, it would become CH3-CHO, would this be a cation because it lost a "negative" charge Cl?

And if, hypothetically, the alpha hydrogen is abstracted, it would be CH2-CHO-Cl, but would it then become an anion because it lost a proton (H+)?

Yes - it will be a carbocation.

One way to think about it is in terms of electronegativity. When you break a bond, the most electronegative atom will get the negative charge and the more electropositive atom will get the positive charge.

In your example, Cl is most electronegative, so when the C-Cl bond breaks the Cl will be negative and the C will be positive.

In your second example, yes, if you lose proton, you will obtain a negative charge.

A weird example is NaOCl (bleach) - in this case, when you break the O-Cl bond, the Cl is the electropositive part (electronegativity = 3.0) and the oxygen is the electronegative part (electronegativity = 3.5).

So the bond breaks to NaO(-) and Cl(+).

Hope this was helpful - James

 

[Ursa]

This is probably a stupid question, but how do you know when someone is a cation or anion?

Ok, so for example CH3-CHO-Cl

If Cl is abstracted by an strong electrophile, it would become CH3-CHO, would this be a cation because it lost a "negative" charge Cl?

And if, hypothetically, the alpha hydrogen is abstracted, it would be CH2-CHO-Cl, but would it then become an anion because it lost a proton (H+)?

CH3-CHO-Cl doesn't exist either...where are you getting your examples from?

 

[bluefish9810]

CH3-CHO-Cl doesn't exist either...where are you getting your examples from?

lol I'm just making stuff up, just as examples.

thanks everyone for the responses, it makes more sense now!