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Topic: Is my understanding of chemical formulae correct?  (Read 19204 times)

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Offline DarkLightA

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Re: Is my understanding of chemical formulae correct?
« Reply #15 on: November 20, 2009, 04:15:44 PM »
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O makes -2 ions.
H makes +
Together, -2+1=-1
So I say that OH has an "ionic charge" of -

That's not bad, but dangerous - sooner or later you will hit element that can have several valencies and it won't be that easy. Besides, OH- is not a compound made of two ions O2- and H+ - it is "just" OH-.
It seems like it works for everything without metals from groups 3-12 (transitionals)

Offline BetaAmyloid

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Re: Is my understanding of chemical formulae correct?
« Reply #16 on: November 20, 2009, 04:49:43 PM »
I'm sure you could find multiple other exceptions that this would not work for...
Discovery consists of seeing what everybody has seen and thinking what nobody has thought - Albert Szent-Györgyi

Offline Borek

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Re: Is my understanding of chemical formulae correct?
« Reply #17 on: November 20, 2009, 05:36:54 PM »
Like - what is formula of carbon oxide? Nitrogen oxide? Phosphorus oxide?
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Offline DarkLightA

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Re: Is my understanding of chemical formulae correct?
« Reply #18 on: November 21, 2009, 06:17:30 AM »
Like - what is formula of carbon oxide? Nitrogen oxide? Phosphorus oxide?


Those aren't part of my 4-step list..

1. Acid + Alkali ==> Salt + water
2. Acid + Metal ==> Salt + hydrogen
3. Acid + Metal Carbonate ==> Salt + CO2 + H2O
4. Metal + H2O ==> alkali  + Hydrogen

And I'm talking about using that method to find output, not input. Btw, you don't really hear much about CO, but CO2, which has an ionic charge of 0.

Offline DrCMS

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Re: Is my understanding of chemical formulae correct?
« Reply #19 on: November 21, 2009, 07:06:26 AM »
There are two oxides of carbon

Carbon Monoxide CO
and
Carbon Dioxide CO2

Borek knew exactly what he was talking about when he gave his examples and there are many others where you simplistic approach breaks down.  That was what he was telling you; learn the real rules behind chemistry rather than making up your own that work initially but then cause you more problems later on.  Now from your thread about your teacher we know your chemistry teacher doesn't know very much chemistry (probably because they do not have any qualifications in chemistry) so we'll try to help you.  But you need to listen to what we say because we do know more chemistry than you.  Borek knew where your approach would fail and tried to steer you away from it.  Both Borek and I have been qualified chemists for longer than you have been alive.  If you are really interested in chemistry buy some of the starter text books listed on the good chemistry books threads.  Read them and then ask questions here.  The problem with trying to learn these things by searching the web is you'll find articles aimed at higher levels than you are ready for.  Things are deliberately simplified at your level so you do not get overwhelmed then as you learn more and more things get more and more complicated as you get closer to reality.

Offline DarkLightA

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Re: Is my understanding of chemical formulae correct?
« Reply #20 on: November 21, 2009, 03:45:31 PM »
There are two oxides of carbon

Carbon Monoxide CO
and
Carbon Dioxide CO2

Borek knew exactly what he was talking about when he gave his examples and there are many others where you simplistic approach breaks down.  That was what he was telling you; learn the real rules behind chemistry rather than making up your own that work initially but then cause you more problems later on.  Now from your thread about your teacher we know your chemistry teacher doesn't know very much chemistry (probably because they do not have any qualifications in chemistry) so we'll try to help you.  But you need to listen to what we say because we do know more chemistry than you.  Borek knew where your approach would fail and tried to steer you away from it.  Both Borek and I have been qualified chemists for longer than you have been alive.  If you are really interested in chemistry buy some of the starter text books listed on the good chemistry books threads.  Read them and then ask questions here.  The problem with trying to learn these things by searching the web is you'll find articles aimed at higher levels than you are ready for.  Things are deliberately simplified at your level so you do not get overwhelmed then as you learn more and more things get more and more complicated as you get closer to reality.

Neither is part of an input for any of the formulas my method works for.

Offline renge ishyo

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Re: Is my understanding of chemical formulae correct?
« Reply #21 on: November 21, 2009, 05:00:10 PM »
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If you are really interested in chemistry buy some of the starter text books listed on the good chemistry books threads.

This is the best advice DarkLightA. The internet may be free, but the information is largely fragmented, and it is not as helpful as reading and working through a general chemistry book that is designed to take you through the subject step by step and build your knowledge in the proper way. I know that there is that feeling that your teacher isn't providing for you and there may be a bit of that youthful rebellion in you that if you have to teach yourself, you might as well throw out *all* authoritative sources on the issue. However, you *do not* have to reinvent the wheel. Working through a good introductory book will help you build a workable knowledge of the subject that is consistent with the way other people are being taught.

Having a knowledge base that is consistent with the way others are being taught is *extremely* important in chemistry. Without it, we simply can't communicate with one another. My main criticism of your teacher's equations is not that they are inaccurate (his equations ARE still accurate in an empirical sense), but rather that this is not the way people are being taught how to write an equation. So people that learn it your teacher's way will be isolated from the other chemists and won't be able to share ideas or build future knowledge in a useful way.

If you want to just make up new rules as you go (like these formulas you are working on), I predict that you will end up just as off base as that teacher is some day, and is THAT what you really want? To become what you are criticizing? (Ooh, it's so Luke Skywalker and  Darth Vadar like!). So get a book that conforms to accepted standards and work through it  ;) The closer you adhere to the standards and rules in a standardized chemical text the better off you will be on standardized tests, on coursework in future classes, and in future correspondence with other chemists. Trust me on this. I know that youthful rebellion boils in you, but modern science is no place for lone rangers...

Offline Borek

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Re: Is my understanding of chemical formulae correct?
« Reply #22 on: November 21, 2009, 06:25:50 PM »
Neither is part of an input for any of the formulas my method works for.

If you prefer to be stubborn - use your methods. We can't forbid you to do it. As we tried to point to you several times - don't be surprised when you hit the wall.

Here is a book that you can download for free:

http://preparatorychemistry.com/Bishop_versions.htm
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Offline DarkLightA

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Re: Is my understanding of chemical formulae correct?
« Reply #23 on: November 22, 2009, 07:11:11 AM »
Okay, I'll have a go at some books  :D

Offline DrCMS

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Re: Is my understanding of chemical formulae correct?
« Reply #24 on: November 22, 2009, 09:04:00 AM »
Good, when you have found one you like and worked through it if you have more questions come back and ask us to help.

Offline DarkLightA

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Offline BetaAmyloid

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Discovery consists of seeing what everybody has seen and thinking what nobody has thought - Albert Szent-Györgyi

Offline DarkLightA

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Offline renge ishyo

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Re: Is my understanding of chemical formulae correct?
« Reply #29 on: November 23, 2009, 04:05:07 PM »
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Are you sure it won't be too hard?

Parts of it are very challenging, yes. Since you are in the 8th grade this may not be the best introduction for you at this point. It IS a book that you will want to read cover to cover one day though so don't forget it (I read it as a junior in college...this book will do more for you than a dozen university level courses). I recommend trying this book at your level:

http://www.amazon.com/Chemistry-Easy-Way-Barrons/dp/0812091388

It is not really an "Easy Way" book (which is why it is criticized), but rather it is a how to prepare for High School  Standardized Tests in Chemistry book (the easy way name got slapped onto it as a marketing ploy because the "dummies" books were so financially successful). Still, it has a good balance of being low cost, simple enough for a beginning student, and yet challenging enough not to be a complete waste of time like most of the other beginner books out there. And because it used to be a how to prepare for standardized tests book, there are MANY problems and even a final exam at the end to allow you to measure your progress. I worked through this book when I was starting out with chemistry, and so I can certify that it works  ;)

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