Balancing Chemical Equations

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Colette Ussery 3L
Posts: 19
Joined: Wed Sep 21, 2016 2:58 pm

Balancing Chemical Equations

Postby Colette Ussery 3L » Tue Oct 11, 2016 12:51 am

I understand the main concepts of how to balance a chemical equation, however for me when the numbers get large and it seems like you're in an endless cycle of balancing the number of mols of one element just to make the mols of another element unbalanced again. Once I know what the correct answer is I can understand how they got it, it's just that for some equations I just have to give up.

For example on the second practice quiz in the workbook #7 we have to balance this equation:

CH3OH + O2 --> CO2 + H20

I went in circles trying to balance this equation with no luck.

But then I checked the answer key and it was super simple:

2 CH3OH + 3 O2 --> 2 CO2 + 4 H2O

I then started over from scratch now knowing that it was possible to solve the equation. Yet again, I couldn't get a balanced equation.

This doesn't happen to me on all balancing equation problems, sometimes I can solve them quickly and easily.

So if anyone could give me a step by step explanation about how this equation was balanced it would be appreciated.

Arianna Brooks 4A
Posts: 18
Joined: Wed Sep 21, 2016 2:57 pm

Re: Balancing Chemical Equations

Postby Arianna Brooks 4A » Tue Oct 11, 2016 1:07 am

In high school I learned how to balance chemical equations by taking "Atomic Inventory." So, what I do is draw a vertical line down the middle of the equation, separating the reactant side from the product side. Then, on each side, write the letter of each element you have and make little "lists" of the number of each element you have. Then, you can try adding different coeffecients into the equation, but when you do, make sure to re - tabulate your atomic inventory list. This way it's easy to compare and know what you still have left to balance. So, for your question:
CH3OH + O2 ---------> CO2 + H2O
(I'll post a picture because it's not posting correctly.)


This just is an easier way of keeping track of all your elements. I hope you find it helpful!!
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Amy Ko 3C
Posts: 24
Joined: Sat Jul 09, 2016 3:00 am

Re: Balancing Chemical Equations

Postby Amy Ko 3C » Wed Oct 12, 2016 10:34 am

A trick you can use when balancing chemical equations is to balance one element (for example Carbon) first, balance another element, and lastly oxygen especially when it is in the form of O2

Given the chemical equation CH3OH + O2 --> CO2 + H2O
Personally, I would balance Carbon first. Both sides have 1 Carbon, so move on to Hydrogen
Reactants side has 4 Hydrogen and Product side has 2 Hydrogen. Thus, Place 2 as coefficient for H2O
Reactants side has 3 Oxygen and Product side now has 4 Oxygen. 4 (on the product side) subtract 1 (on the reactant side in CH3OH) gives 3. You place 3/2 as coefficient of O2 (since you need 3 Oxygen, but 3(O2)= 6 O and you need 3/2 (O2) = 3 O)
Then multiply the entire chemical equation by 2
The final balanced chemical equation is 2 CH3OH + 3 O2 --> 2 CO2 + 4 H2O

Colette Ussery 3L
Posts: 19
Joined: Wed Sep 21, 2016 2:58 pm

Re: Balancing Chemical Equations

Postby Colette Ussery 3L » Fri Oct 14, 2016 3:49 pm

Thanks

Katrina_Domingo_3G
Posts: 23
Joined: Wed Sep 21, 2016 2:59 pm

Re: Balancing Chemical Equations

Postby Katrina_Domingo_3G » Sat Oct 29, 2016 12:57 pm

In balancing chemical rxns for the midterm, are we supposed to know the states of matter for the uncommon compounds or will they be given?

Yesenia Munoz 1G
Posts: 22
Joined: Wed Sep 21, 2016 3:00 pm

Re: Balancing Chemical Equations

Postby Yesenia Munoz 1G » Sat Oct 29, 2016 4:27 pm

Are we allowed to use fractions when balancing chemical equations as long as we put the coefficient at the front of the equation?

Amy_Bugwadia_3I
Posts: 37
Joined: Wed Sep 21, 2016 2:56 pm
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Re: Balancing Chemical Equations

Postby Amy_Bugwadia_3I » Sat Oct 29, 2016 5:23 pm

Yesenia Munoz 1G wrote:Are we allowed to use fractions when balancing chemical equations as long as we put the coefficient at the front of the equation?


I think that if you do use fractions as coefficients in balancing equations, that should only be an intermediate step. Your final answer should always be whole number coefficients. If you do have fractions as coefficients, multiply the entire equation by the denominator in order to obtain whole numbers.


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