CH3COONa or NaCH3COO? (1 Viewer)

[hs17]

Which one's more correct? My teacher writes the 2nd way but I thought the 1st way is more correct...?

 

[Qeru]

Which one's more correct? My teacher writes the 2nd way but I thought the 1st way is more correct...?

Both are fine, in the context of organic chemistry the first way makes sense, in the context of acid/base second way makes sense but overall both are perfectly fine. (atleast for HSC, CM_tutor might have some uni level explanation as to why one is better lol).

 

[hs17]

Okay, tysm. I'm doing acid-base rn so i'll stick to the 2nd one

 

[CM_Tutor]

My preference is CH₃CO₂Na

 

[Eagle Mum]

Since the IUPAC molecular formula C2H3NaO2 is seldom used, I agree with Qeru’s suggestion of using whichever alternative highlights its role.

 

[CM_Tutor]

• These are not molecular formulae, they are condensed structural formulae.
• US textbooks have a habit of using molecular formulae, like C₂H₄O₂ for acetic acid and C₂H₃O₂^- for the acetate ion, leading to writing sodium acetate as NaC₂H₃O₂ if writing a cation-anion formula (like NaCl) or C₂H₃NaO₂ as a molecular formula (C then H then other elements in alphabetical order by symbol).
• US books sometimes emphasises the acidity by presenting acetic acid as HC₂H₃O₂ and thus sodium acetate as NaC₂H₃O₂.
• Condensed structural formula are chosen to reflect the sequence of bonding, hence acetic acid as CH₃COOH. In the salt form, the cation is associated with the negative charge of the carboxylate group of the acetate ion and not with the methyl group, hence the formula CH₃COONa being more appropriate than NaCH₃COO.
• My preference for CH₃CO₂Na is because the two O atoms are distinctly different in the acid form, one with a double bond to the carboxylate C atom, the other with a C to O single bond and an O to H single bond. This is sometimes written as CH₃-C(=O)-OH. In the acetate anion, the two O atoms are equivalent and identical. The C atom has a single bond to each O atom with the negative charge distributed over both oxygen atoms, which share a three-centre-2-electron bond. We often write it as having C=O and C-O^- bonds but this is not an accurate representation, using -CO₂^- is a more accurate representation.
• Having said all of this, absent some specific in the way the question is structured, I can't see why either representation should be unacceptable.

 

[Eagle Mum]

To be clear, I was never suggesting that the original options presented in this thread were molecular formulae.
I’m merely commenting that IUPAC confines its definitions to the molecular compound so that every molecule could have a unique standardised name. Everything else is based on the context of usage which you have explained in detail.

 

[someth1ng]

Use the first way. I've never seen the second way be used anywhere.