[cjp88]

Hello, I'm running into some problems naming these reactions.

1.    Provide the correct IUPAC name for each substance in the following reactions:
   
a.    CaCO3(s)CaO(s) + CO2(g)
<Solid calcium carbonate produces solid calcium monoxide and carbon dioxide gas.>
b.    Ca(OH)2(s) + 2 NH4Cl(aq)CaCl2(aq) + 2 NH4OH(aq)
<When you mix solid calcium dihydroxide and aqueous diammonium chloride it will produce aqueous calcium dichloride and aqueous diammonium monohydroxide.>
c.    H2S(aq) + PbCrO4(s)PbS(s) + H2CrO4(aq)
<When you mix aqueous hydrosulfuric acid and solid lead chromium tetraoxide it will produce solid lead monosulfide and aqueous dihydrogen chromium tetraoxide.>

My course has lack of documentation of how to name reactions.  What I have in blue is my answer, but I feel they're all wrong and if not can be improved.  For 2 NH4Cl(aq) I'm not sure what the 2 in front stands for.  This is very frustrating because I've read my course up to this point and understood every single concept fine then I get these questions and I'm left clueless.

Thanks to anyone who can provide some help.

[sjb]

Hello, I'm running into some problems naming these reactions.

I think these are fine as far as they go, but there are other, more common (if not necessary IUPAC) names for many of these reagents

1.    Provide the correct IUPAC name for each substance in the following reactions:
   
a.    CaCO3(s)CaO(s) + CO2(g)
<Solid calcium carbonate produces solid calcium monoxide and carbon dioxide gas.>

Obviously it depends what sort of level you're at, but I'd personally name CaO as simply calcium oxide (there are no really common, stable combinations of the two)

b.    Ca(OH)2(s) + 2 NH4Cl(aq)CaCl2(aq) + 2 NH4OH(aq)
<When you mix solid calcium dihydroxide and aqueous diammonium chloride it will produce aqueous calcium dichloride and aqueous diammonium monohydroxide.>

Again, the mere fact that it's calcium would suggest leaving out the "di" here in dihydroxide. The reason I'm emphasising the calcium here is that in some cases, e.g. iron, you can get Fe(OH)₂, and Fe(OH)₃. These can be named iron dihydroxide and iron trihydroxide, though better may be using things like Stock Nomenclature to get iron(II)hydroxide, and iron(III)hydroxide.

 The other 2 2's (before ammonium hydroxide and ammonium chloride) show that you'd need (or produce) 2 equivalents of each in the balanced equation. Whether you need, or want, to put this extra information in is mostly up to you, it may be important in the future if you come across a reaction that has reactants that can react in a 1:1 mixture, and then go on to react again.

c.    H2S(aq) + PbCrO4(s)PbS(s) + H2CrO4(aq)
<When you mix aqueous hydrosulfuric acid and solid lead chromium tetraoxide it will produce solid lead monosulfide and aqueous dihydrogen chromium tetraoxide.>

This one is a bit different, as you may need to know the fact that the CrO₄^2- anion has a common name other than "chromium tetraoxide". In my opinion, chromium tetraoxide would refer to the neutral species, so using it here is actually wrong. But I'm not sure how much work you've already done, or your syllabus - I'm noticed in some cases naming of complex ions and the like is done before you reach this stage, and others it's after.

My course has lack of documentation of how to name reactions.  What I have in blue is my answer, but I feel they're all wrong and if not can be improved.  For 2 NH4Cl(aq) I'm not sure what the 2 in front stands for.  This is very frustrating because I've read my course up to this point and understood every single concept fine then I get these questions and I'm left clueless.

Thanks to anyone who can provide some help.

I wouldn't say the answers are wrong, but can be better, but would need to know what you've already done in order to better advise.

S

[cjp88]

Hello, thank you for the time in responding to my questions.

For CrO4^2- that was my own mistake, I should of put chromate not chromium tetraoxide.

The only thing I'm not sure about is 2 NH4Cl(aq).  Would I write it as aqueous diammonium chloride or just aqueous ammonium chloride.  I'm confused on how to word that two of NH4Cl(aq) are being used.

My level isn't that high in Chemistry.  I'm taking Chemistry 20.  What I did learn for Chemistry in my Science 10 and 20 can be scrapped out the window due to such a poor course in my opinion.  Lets just say the overall class average for the exam was around 40%.  So pretty much I understand the basics to naming, just learning on how to word reactions.

[sjb]

Hello, thank you for the time in responding to my questions.

For CrO4^2- that was my own mistake, I should of put chromate not chromium tetraoxide.

The only thing I'm not sure about is 2 NH4Cl(aq).  Would I write it as aqueous diammonium chloride or just aqueous ammonium chloride.  I'm confused on how to word that two of NH4Cl(aq) are being used.

I would probably just say that "solid calcium hydroxide reacts with two equivalents of aqueous ammonium chloride to yield aqueous calcium chloride and two equivalents of aqueous ammonium hydroxide. Diammonium chloride to me would suggest something like (NH₄)₂Cl (sic), a bit like disodium phosphate Na₂HPO₄ as opposed to sodium phosphate NaH₂PO₄.

My level isn't that high in Chemistry.  I'm taking Chemistry 20.  What I did learn for Chemistry in my Science 10 and 20 can be scrapped out the window due to such a poor course in my opinion.  Lets just say the overall class average for the exam was around 40%.  So pretty much I understand the basics to naming, just learning on how to word reactions.

Sorry, this ("Chemistry 20", "Science 10" etc) doesn't really mean much to me - I guess my education system is different to yours, but from what you're saying I'm guessing you're around 14-15 or so (at least, compared to what I remember doing in chemistry at school / university etc) - apologies if this is not the case.

S

[cjp88]

Sorry for the confusion.  I'm 18 years old upgrading my sciences.  Science 10 means Grade 10 (Year ten, first year of high school) and Science 20 refers to Grade 11 (Year elven, second year of high school).  They're both academic courses as well, the highest you can take.  Chem 20 is the Grade 11 level Chemistry, then Chem 30 which is the last year, Grade 12 which is also the highest level you can take for these courses.

So I was trying to say that because my Grade 10 and 11 science courses were not the best it's catching up with me now when I need to understand these concepts.

[Borek]

The only thing I'm not sure about is 2 NH4Cl(aq).  Would I write it as aqueous diammonium chloride or just aqueous ammonium chloride.  I'm confused on how to word that two of NH4Cl(aq) are being used.

Two in front is not part of the molecule formula. Read 2^nd paragraph on this page:

http://www.chembuddy.com/?left=balancing-stoichiometry&right=stoichiometric-calculations

[cjp88]

The only thing I'm not sure about is 2 NH4Cl(aq).  Would I write it as aqueous diammonium chloride or just aqueous ammonium chloride.  I'm confused on how to word that two of NH4Cl(aq) are being used.

Two in front is not part of the molecule formula. Read 2^nd paragraph on this page:

http://www.chembuddy.com/?left=balancing-stoichiometry&right=stoichiometric-calculations

Thanks!  I'm starting on balancing in my course now so I should be able to understand more shortly.  Thanks again!