Balancing Equations

Balancing li + o₂ -> li₂o

gives

4li + o₂ -> 2li₂o

doesn't it?

Jon

Edit: ^^ Antar got there first. He said the same thing as me though.
 
Eh... :(

Is that at GCSE level though? We're only trying to balance the numbers out, giving me a headache :(
 
Sinque said:
Eh... :(

Is that at GCSE level though? We're only trying to balance the numbers out, giving me a headache :(
Click to expand...

You need to have the same number of atoms of each species on either side, but you can't physically alter the species themselves like you have with Lithium Oxide - the formula is fixed for it. You have to alter the coefficients in front of the different species until you have the same amount of constituent atoms on each side. (in your case, Li and O)

(and I know, Li2O2 is a substance but if you're given the unbalanced equation with Li2O then you should balance for that substance rather than altering the chemistry of the reaction)
 
Last edited:
Dave said:
You need to have the same number of atoms of each species on either side, but you can't physically alter the species themselves like you have with Lithium Oxide - the formula is fixed for it. You have to alter the coefficients in front of the different species until you have the same amount of constituent atoms on each side. (in your case, Li and O)
Click to expand...

I see, so it's wrong?
 
Did a bit of a ninja edit!

Li2O2 is a substance, but if you're given an unbalanced equation involving Li2O then you should balance for that. The correct balances are given above:

2Li + 1/2O2 = Li2O

Or

4Li + O2 = 2Li2O

Take your pick really, I'd usually go for the top one but some chemistry teachers don't like using fractions as coefficients. (I do chemical engineering not chemistry, so it's all the same to me :p)
 
Ah, I understand now. I did it again and got that answer, going on to a harder one now. I'll report back, cheers :)
 
markyp23 said:
You cannot change the chemical formula. You can only add numbers before each of the "terms" in the equation. You need to get the number of each "chemical" the same on both sides.
Click to expand...

Yes I understand that now, can you check the previous one? Cheers :)

Edit: Hurray, cheers guys. Was expecting to get flamed with 'do your own homework!' :P But I guess I did try :)
 
You seem to be getting the idea with the second one. As has been said, just remember that each group cannot be changed, because that makes a different chemical - eg you couldn't change H2O in the second one to H2O2, as that's changing water into bleach ;).

You should really always use caps when writing out chemical forumlae, as it's a standard and you'd be marked down in an exam for not using them, so you should be writing Li, Na etc.
 
Sinque said:
Yes I understand that now, can you check the previous one? Cheers :)

Edit: Hurray, cheers guys. Was expecting to get flamed with 'do your own homework!' :P But I guess I did try :)
Click to expand...

That's just the mathematicians, us chemists/chemical engineers look out for one another ;)

Looks like you've got it now!
 
You must log in or register to reply here.
Back
Top Bottom