[ShannonC_77]

Hi,

I'm trying to teach myself chem 30 right now so I can take chem 101 at university next year (working on my second degree).

What I don't understand right now, is whether the charge on a diatomic molecule gets multiplied in when you are trying to balance it.

For example, take

C + S8 (lower case

The answer I'm told is CS2

So looking at this, the C ion has a charge of +4 (hopefully I'm right on that) and then the S8 molecule has a charge of -2.  So I would multiple 8 X -2 to get -16 and then this needs to balance out with the +4 charge on the C.

But the answer states it's CS2 , which doesn't make sense to me. Do you just ignore the subscript 8 on the C in the second half of the equation?

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then another problem:

N2 + O2              and the answer they give is N2O

But if the Nitrogen has a charge of (-3) and oxygen has a charge of (-2), how does that work? Do I just need to memorize the equations for diatomic molecules?

[Borek]

Ignore charges, just balance atoms. You have to balance charges ONLY when they are 'visible' - ie some of the substances are in ionic form.

See balancing chemical equation lectures on my site.

However, now that I think about it - are you sure you are asking about balancing equations, not about predicting molecule formulas? If you have an equation given as C + S₈ -> CS₂ you don't have to think WHY it is CS₂, you just have to find correct coefficients so that number of atoms of all elements will be identical both before and after reaction.

Predicting formulas is completely different thing - and it needs some memorization.

[ShannonC_77]

Thanks for your prompt reply. I have a feeling your site will come in very useful to me, right now and in the next few weeks as I progress.

I think you're right, I was getting slightly confused and it was a bit of both - first predicting why it was CS2 as that in itself didn't seem to make sense, but then when I added in the charges I got even more confused.  I'll try working through a few more equations now with this in mind. I think it clarifies it much better now.

Thanks again!