Balancing Equations

Hi, I’m currently doing some transition work for A level chem and am slightly confused whilst balancing this equation. The equation in question is S8 + O2 ———> SO3 and I have balanced it to S8 + 12O2 ——-> 8SO3 however whilst writing some rules up from a website one of the rules was that the final set of coefficients should be whole numbers with no common factors other than one. The issue is that 12 and 8 have common factors of 2 and 4 but I have tried changing the coefficients and it hasn’t worked for me as you need 8 Sulphur??? Any help would be much appreciated! :smile:

Reply 1

SusannaW

The balancing you’ve done seems fine- what website were you looking at?

Reply 2

GabiAbi84

Original post by carxlinefxrbes_

Hi, I’m currently doing some transition work for A level chem and am slightly confused whilst balancing this equation. The equation in question is S8 O2 ———> SO3 and I have balanced it to S8 12O2 ——-> 8SO3 however whilst writing some rules up from a website one of the rules was that the final set of coefficients should be whole numbers with no common factors other than one. The issue is that 12 and 8 have common factors of 2 and 4 but I have tried changing the coefficients and it hasn’t worked for me as you need 8 Sulphur??? Any help would be much appreciated! :smile:

Your answer is correct.

Remember that S8 also has a coefficient of 1 even though it isn’t written down. So you have three coefficients : 1, 8, and 12: and these three only have a common factor of 1.

The rule is there so you use the lowest numbers possible :
(To use an algebraic example)
if you had

4y -> 8z

you could simplify it down To

2y -> 4z

(edited 3 years ago)