How can I effectively balance chemical equations for an upcoming exam?

[kchan]

Okay, this is a bit stupid, but I have an exam tommorrow, and I have no idea how to balance chemical equations. (A bit late for studying, I know) but if anyone can help me, that'd be great. I just want to know how to balance it, and why. And any rules and tips would be great.

 

[thunderfvck]

SO easy.
Just balance the equation. You want it balanced in the sense that you have the same number of elements on both sides. When you have a number in front (a coefficient) of any series of letters, like 2H2O, that means you have 2*2 = 4 H's and 2*1 = 2 O's. So it's up to you to balance the equation by putting the right coefficients in front of the letters. BTW the letters actually symbolize chemicals but you probably knew that.

ie. 2H2 + O2 --> 2H2O


H's (on left) --> 2H2 --> 2*2 = 4 <-- 2H2O <-- (on right) H's
O's (on left) --> O2 --> 2*1 = 2 <-- 2H2O <-- (on right) O's

So now you understand what you actually HAVE to do, but now you need a method for doing it. I'll show you how I normally do it...

ie. CH4 + O2 --> H2O + CO2 <--- Unbalanced. l=left, r=right

C's (l): 1 C's (r): 1
H's (l): 4 H's (r): 2
O's (l): 2 O's (r): 3

Those are the total number of elements on each side. Notice how we have the same number of C's, so we're good for that, for now. But we need 4 H's on each side...
So:

CH4 + O2 --> 2H2O + CO2 <--- I put a coefficient of 2 before H2O.
makes:

C's (l): 1 C's (r): 1
H's (l): 4 H's (r): 4
O's (l): 2 O's (r): 4

Now we have to balance the O's.

CH4 + 2O2 --> 2H2O + CO2 <--- I put a coefficient of 2 in front of O2

C's (l): 1 C's (r): 1
H's (l): 4 H's (r): 4
O's (l): 4 O's (r): 4

So it's balanced!
Listen. You shouldn't have to write out these tables everytime you add a new coefficient. You should be able to do it all in your head. But if oyu can't you can always put numbers right below the elements to kind of keep tab on everything. Anyways, you got the idea of how it works now, so all you have to do is practise practise...

http://dbhs.wvusd.k12.ca.us/Equations/Balance-Worksheet1.html
http://dbhs.wvusd.k12.ca.us/Equations/Balance-Worksheet2.html

There's 100 questions for you to practise with.
You know I just wasted a lot of my time writing this out. There are a lot of resources you could have looked up for answers to your question. If I knew you I'd expect some kind of sexual proposition, especially if you have an older (hot) sister. Learn to use the search engine THEN ask if you're clueless. lazy LAZY LAZY.

 

[ravenprp]

Hi there,

First of all, it's great that you are reaching out for help with balancing chemical equations. It can be a tricky concept, but with some practice and understanding, you'll be able to do it with ease.

To start, let's go over the purpose of balancing chemical equations. Essentially, balancing equations ensures that the same number of atoms of each element are present on both sides of the equation. This is important because in a chemical reaction, the number of atoms must be conserved.

There are a few rules and tips that can help you when balancing equations:

1. Start by counting the number of atoms of each element on both sides of the equation. This will give you an idea of which elements need to be balanced.

2. Begin by balancing the elements that appear only once on each side of the equation. This will make it easier to balance the remaining elements.

3. Use coefficients (numbers in front of the chemical formulas) to balance the equation. Remember, coefficients can only be placed in front of the entire molecule, not individual atoms.

4. Make sure to check that all elements are balanced after you add coefficients. If they are not, adjust the coefficients until they are balanced.

5. It's also important to remember that the coefficients should be in the simplest whole number ratio.

Practice makes perfect, so I would suggest working through some practice problems to get more comfortable with balancing equations. You can also find some helpful videos and tutorials online.

Best of luck on your exam tomorrow! Just remember to take your time and double check your work. You got this!