Writing the balanced equations

[unkown2]

Can someone give the balanced equations for these?

 

sulfur dioxide + oxygen =sulfur trioxide

 

methane + oxygen = carbon dioxide + water

 

Aluminum chloride + pottasium = potassium chloride + aluminum

 

ammonia gas + oxygen +nitrogen + water

 

copper(II) oxide = copper + oxygen gas

 

Thanks

[blike]

I'll do one, you need to try the rest..

 

CH3 (methane) + O2 (molecular oxygen) = CO2 (carbon dioxide) + water (H2O)

 

First, lets balance the oxygens...

 

There are two oxygen molecules on the left, and 3 on the right. Whats the lowest common factor of two and three? 6! So put a factor into each side which will yield six oxygens on both sides.

 

CH3 + (O2)3 = (CO2)2 + (H2O)2

 

Now, there is one carbon on the left, and two carbons on the right hand side of the equation. Balance those.

 

(CH3)2 + (O2)3 = (CO2)2 + (H2O)2

 

But now we have six hydrogen on the left, and 4 on the right. thus, we need to add two more hydrogens to the right hand side.

 

(CH3)2 + (O2)3 = (CO2)2 + (H2O)3

 

Now, because we've added the "3" factor in front of H2O to balance our hydrogens, we've thrown our oxygen count off. There is now 7 oxygens on the right, and 6 oxygens on the left. How do we reconcile this since oxygens can only be added in paris of two? Add 1/2 (O2) to the left side.

 

(CH3)2 + (O2)3.5 = (CO2)2 + (H2O)3

 

Now the equation is balanced. However, we cannot have 3.5 molecules of oxygen. So, in order to get rid of the fraction, we double all the numbers.

 

(4)CH3 + (7)O2 = (4)CO2 + (6)H2O

[greg1917]

Of course it would be useful to remember that a methyl group is CH3, while the compound methane is CH4.

 

Thus the actual equation should be as follows.

 

CH4 + O2 ---> CO2 + H2O

 

You need to balance this. For reference, the numbers in front of the compounds are referred to as 'stoichometric coefficients' (sp?) but thats pretty esoteric knowledge.

 

In any case, looking at the equation, the number of carbons are balanced on both sides at 1. So you should leave the CH4 and CO2 alone if you can.

 

Put a 2 in front of the H2O to balance the hydrogen atoms, making that 4 on each side.

 

CH4 + O2 ---> CO2 + 2 H2O

 

The only remaining unbalanced thing is oxygen. You have 2 atoms on the left and 4 on the right. Easily solved, put a 2 in front of the O2, making it 4 and finishing the balancing act.

 

CH4 + 2 O2 ---> CO2 + 2 H2O

 

Ignore Blike's post. He means well, but you just cant juggle double whiskies and chemistry, unless you're a whisky chemist. which Blike isnt.

[blike]

rofl, oh crap

[aommaster]

The best technique in balancing equations is to balance one type of atom at a time, and "POOF" the whole equation is balanced. You just need practice. Remember, the more you practice, the better you get!

[blike]

too much organic chemistry . I'm not used to ever seeing a CH4 molecule. methyl this, methyl that.

 

ignore me, listen to greg.

[aommaster]

hmmmm.... I actually LIKE organic chemistry LOL

[greg1917]

Yeah, organic chemistry can be really interesting but I really find the more complex aspects of carbohydrate chemistry hard to fathom. Perhaps I just need a decent lecturer to point out the finer points but most of the stuff goes right over my head

[aommaster]

yeah. I know. It does get a little complicated, but, its also easy if u understand the stuff. I'm doing GCSE, and I already understand a bit about alkyne,s cycloalkanes, alkadienes, diynes, trienes, triynes and a load of other stuff!

[VendingMenace]

it gets really complicated when they require you to learn the so-called "named" reactions. Mostly becuase it is brute memerization and there are lotsa different methods (thousands). HOwever, if you just want to learn the theory behind reactions, there is a really good ~300 pg book called the art of writting reasonable organic reaction mechanisms byRobert Grossman. It is by far the best ochem book i have ever had, hands down. It is a no-nonsense, concise, and complete approach to writting mechanisms for reactions. IN six chapters and 300 pages (quite short for an ochem book) Grossman will take you through all of the basic reactions we find in ochem (addition and elimination in acidic and basic conditions, cyclization reactions, rearangements, readical chemistry, ect). The book emphazises theory rather than memorization. Grossman quickly presents why various types of reactions occur and why certain types of reactions will happen over competing reactions. Then he solves a few examples and moves onto the next topic. At the end of each chapter are many, many problems.

 

I cannot stress enough, how good this book is. In just one quarter in grad school i learned probably twice as much as i did in my year long undergrad course. And while my proffesor was quite good, and had much to do with that, this book is amazing. SO if you want a book that will teach you why things happen in ochem and you don't want once of those crappy verbose books that you prolly already have -- buy this one, it will open up the world of ochem to you.

 

 

 

One caveat -- naming is not covered in this book. At times, gossman will refer to a compound by its name, and if you don't know what he is talking about you will be out of luck. Fortunately, it is rare that he talks about something without a diagram, but for those few cases, it should not be too hard to look it up on the internet -- or ask someone ont this forum

[wolfson]

unkown2 are you studying G.C.S.E. (1AC) chem?

 

VendingMenace i must say once you have understood the functional groups in organic chemistry equations are not that bad.

[VendingMenace]

why memorize functional groups, when you can just understand why things are nucleaophilic, or electrophilic and if they are stericly hyindered or not? With just a basic understanding of the thoery, you can give reasonable reaction mechanisms without any undestanding of the functional groups.

 

Not that it is not important to know these groups -- of course it is. I just htink that ochem is taught incorrectly in undergrad. Rather than saying, "this is such and such a functional group and it will behave in such a way" and then having people memorize functional groups, they should say, "electronegative atoms are electron withdrawing. Groups that are connected to an eletronegative atom are electrphilic." and so on. IN such a way, you can learn all of ochem in one quarter. Then, once you understand the theory, spend a quarter learning to name things. Then, when you are done with that, spend a quarter learning spectroscopy.

 

I think that is a much better year long course. IMO

[wolfson]

I dont know if you are aware of the undergraduate chemistry syllabus, in the UK, i am. I was not just taught to memorise functional groups, the vast knowledge base, is organic chemical theories, to be able to identify a functional group, is the basic knowledge that you need, that is all i was saying.

[unkown2]

Thank you to the guys that helped me.

 

Wolfson-

I am doing Science grade 10 and we are doing chemistry thats why I need help on the equation.(My teacher doesn't really teach us so we just to teach ourselves.And I need help so I asked it here)

 

Thanks again!

[aommaster]

Well what luck, i'm in my second year of gcse (so any problems, send me a PM) you can even add me to ur buddies list of u like!