[JoeJoe]

Hi there, another question from me

I have some homework to name the following compounds:

A) Na2SO4
B) Na2CO3
C) CuCO3
D) CuSO4 5H2O
 
I think they are called

A) Sodium(II) Sulfate
B) Sodium(II) Carbonate
C) Copper Carbonate
D) Copper Sulfate (What is the 5H2O called?, does it change the name?)

[Ak]

the first 3 are right and the last one can be called Copper Sulfate, but the 5 H2O shows that its not anhydrous.  when its written with the 5H2O its called copper sulfate pentahydrate.

[Astrokel]

hello joejoe,

i don't think there is a need to put (II) as sodium has only 1 oxidation state which is +1, but the (II) suggests a +2. So just sodium carbonate and sulphate.

[cliverlong]

hello joejoe,

i don't think there is a need to put (II) as sodium has only 1 oxidation state which is +1, but the (II) suggests a +2. So just sodium carbonate and sulphate.

Hi Astrokel

I agree with you about 90% but I would be a bit more "formal" than that.

I claim that writing "sodium (II) something" is wrong

rather than write there is no need to put the "(II)"

because


writing "sodium (II)" suggests sodium can have an oxidation state of 2 (which it can't - I believe).


The subscript numbers for a particular element in a molecular formula, e.g. the 2 and 3 in Na₂CO₃, give the number of atoms of that element in a molecule of the compound. The oxidation state is a different, but related idea.


Clive

[Borek]

I claim that writing "sodium (II) something" is wrong

And you are right.

[Guitarmaniac86]

Hi there, another question from me

I have some homework to name the following compounds:

A) Na2SO4
B) Na2CO3
C) CuCO3
D) CuSO4 5H2O
 
I think they are called

A) Sodium(II) Sulfate
B) Sodium(II) Carbonate
C) Copper Carbonate
D) Copper Sulfate (What is the 5H2O called?, does it change the name?)

For your last question, you would name it CuSO4.5H20 as copper sulphate pentahydrate, where penta means five and hydrate means water. The rest of your questions have been answered so I wont go into those.

[DrCMS]

The copper salts should have numbers as copper can be +1 or +2
i.e.
Cu₂O is Copper(I) oxide
but
CuO is Copper(II) oxide

[AWK]

and more correct: sulfate(VI)

[JoeJoe]

Hey guys, thanks for the awesome responses.

So anything elements with + _H2O is considered hydrate?
the 5 just denotes the prefix (5, penta, as you mention)

1-mono
2-di
3-tri
4-tetra
5-penta
6-hexa
7-hept
8-octa
9-nona
10-deca

correct?


For example (I found this via google):

Co(H2O)6Cl2 is called "Cobalt(II) chloride hexahydrate"
Why is it not called Cobalt Hexahydrate Chloride?

Does Hydrate always go at the end of the name?

[AWK]

search textbook or internet for nomenclature of  hydrates and aqua complexes

note

7-hept

should be hepta

[rahul2ghosh]

For example (I found this via google):

Co(H2O)6Cl2 is called "Cobalt(II) chloride hexahydrate"
Why is it not called Cobalt Hexahydrate Chloride?

Does Hydrate always go at the end of the name?

Hello,

What I can recollect is...

If it is a plain hydrate of an ionic salt, then the formula and name should be:

CoCl₂.6H₂O  --->  Cobalt(II) Chloride Hexahydrate

Now hexahydrate is named after chloride and not vice versa since the it is the compund cobalt(II) chloride that has 6 molecules of water of crystalisation.

However, if it is a co-ordinate compound then the formula should be:

[Co(H₂O)6Cl₂]      Hexaaquadichlorocobalt(II)


Hope this helps.