ebrown_p wrote:(thanks for the heads up roger...)
Blossom,
I think you are confusing the term "balanced" with what is correct.
The chemical reactions you are studying are a way to express what happens in nature. As you are learning not, not every reaction that you can write is something that would happen in nature.
Your version of the reaction is perfectly balanced. There are the same number of each type of atom on each side of the reaction. This is all you need to do to have a balanced equation.
However, your teacher's version is also perfectly balanced. You should check to make sure this is true (but it is).
So, they are both balanced.... how do you know which is correct?
Well, the real question is which of these to reflects something that happens in the real world.
To know this, you need to know a bit more about chemistry than how to balance equations.
One big clue that your version is not correct is that ClO3 is an ion (i.e. it gains an extra electron). For your version of the reaction to be correct the other product (K) would have to gain an electron. This, for example, is a proper reaction (and I happen to know that this happens in nature)...
KCl03 -> K+ + ClO3- (these are ions and you may not have learned about these yet).
Another big clue is that in nature you never find K2. Two Potassiums do not form a "diatomic" molecule (but Oxygen atoms do). Again, this is something you have to learn in addition to balancing equations.
Your teacher is correct. The equation she gave you is for the decomposition of Potassium Chlorate.
I also assume that she gave you enough information on how to figure this out.
Often teachers will give you the products and the reactants without the coefficients, and ask you to figure the coefficients, for example...
.. _____KClO3 -> _______ KCl + _______ O2
Other times teachers will tell you what type of reaction it is and let you figure out the products for yourself. For example, I might ask my students "Potassium Chlorate decomposes producing Potassium Chloride and Oxygen gas... write a balanced equation for this reaction.
You have to understand what the teacher is asking and what skills you need to solve it.
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I have rambled enough. The point is that there is a lot more to chemistry than balancing equations. You got the balancing down on this one, but you seem to have missed the point of the problem.
You didn't tell us the context of the problem (i.e. what other information you were given, and what you have been taught).
Try to ask your teacher what you should have known to solve this problem (other than balancing).
Or, if you would like, you can post the whole problem with all the information and instructions and we can hash it out here with you.
thank you for the explanation!
I'm not sure which chapter the question would've been for, but I think it's from "Types of Chemical Reactions and Solution Stoiciometry". The whole question was:
Balancing Equations
Write correctly balanced equations for these expressions:
Then there were five equations for that question and they were:
1) H2(g) + O2 (g) ->
2) KClO3 ->
3) KBr + MnO2 + H2SO4 ->
4) AgCl(s) + NH3 (aq) ->
5) Cu + H2O (g) ->
I really don't understand how to balance these (except for number one). I'm so confused! Could you help me again if it's not too much trouble?
The answers are:
1) 2H2 (g) + O2 (g) -> 2H2O
2) 2KClO3 -> 2KCl + 3O2
3) 2KBr + MnO2 +2 H2SO4 -> 2K^(+1) + Br2 + Mn^(2+) + 2H2O + 2SO4 ^(2-)
4) AgCl (s) + 2NH3 (aq) -> Ag(NH3)2 ^(+1) (aq) + Cl^(-1) (aq)
5) Cu + H2) (g) -> Cu2+ (aq)
The solutions kind of make sense to me, but i don't know how i would find them on a test. it's really depressing.
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