Balancing equations with fractions [ENDORSED]

Alondra Juarez section 1E
Posts: 47
Joined: Fri Sep 29, 2017 7:03 am

Balancing equations with fractions

Balancing equations can be quite confusing when fractions get involved for me. For example for the chemical equation NH3+O2--------->NO+H2O I balanced it and obtained the answer 2NH3+(5/2) O(2)-------->2NO+3H2O, could I leave the fraction or would I have to multiply the whole equation by two in order to get rid of the fraction?

Sunjum Singh 1I
Posts: 30
Joined: Fri Apr 06, 2018 11:05 am

Re: Balancing equations with fractions  [ENDORSED]

Normally having a fraction isn't ideal, but you're right about multiplying the whole equation by 2 in order to cancel out the fraction and make everything whole numbers. So it would become 4NH3+5O(2)---->4NO+6H20 I believe.

Emma Leshan 1B
Posts: 30
Joined: Fri Apr 06, 2018 11:03 am

Re: Balancing equations with fractions

Definitely multiply the whole thing by 2. Dr Lavelle said in class that stoichiometric coefficients should be whole numbers.

Alma Flores 1D
Posts: 64
Joined: Wed Nov 08, 2017 3:01 am

Re: Balancing equations with fractions

Yes, you have to multiply by 2 to cancel out the fraction. The stoichiometric coefficients should be whole numbers, not fractions.

Isabella Barkett 1G
Posts: 24
Joined: Fri Apr 06, 2018 11:01 am

Re: Balancing equations with fractions

Also it is easier to use whole numbers as it would be simpler to decipher the mole ratio between reactants and products.

Amir Akhavan 1E
Posts: 34
Joined: Fri Apr 06, 2018 11:01 am

Re: Balancing equations with fractions

Stoichiometric coefficients should be whole numbers so therefore you should multiply all coefficients by 2. This would make the equation easier to understand as there would be no messy fractions.

Posts: 35
Joined: Fri Apr 06, 2018 11:02 am

Re: Balancing equations with fractions

I think this idea is also similar to when we create the empirical formulas. The idea to keep the stoichiometric coefficients whole numbers. For example, if after dividing the moles of a particular element by the smallest number of moles there is still a fractional number, then you would also multiply it by any number in order to find the closest whole number.

Faisal Alshamaa - 1L
Posts: 31
Joined: Fri Apr 06, 2018 11:01 am

Re: Balancing equations with fractions

I think it is best to have the coefficients be whole numbers and not fractions. However, it is also important to remember that if you are asked something like how many moles of the other reactant (oxygen) are needed when there are only two moles of ammonia the answer would then be (5/2) or 2.5 .

Paywand Baghal
Posts: 32
Joined: Fri Apr 06, 2018 11:01 am

Re: Balancing equations with fractions

All stoichiometric coefficients should be whole numbers and in order to cancel out the two, you can multiply the entire equation by 2. By doing this, you must multiply 2 to every single part of the equation and not just the coefficient fraction you are trying to make whole.

Jamie Reniva 1J
Posts: 14
Joined: Wed Nov 15, 2017 3:00 am

Re: Balancing equations with fractions

Stoichiometric coefficients shouldn't be in fraction form because I think that it would indicate that you have to split an atom in half and that's not possible. It is better if you multiply the whole equation by 2.

YeseniaGomez_1L
Posts: 32
Joined: Fri Apr 06, 2018 11:02 am
Been upvoted: 1 time

Re: Balancing equations with fractions

The coefficients must be in whole numbers so you would have to multipy the whole equation (both sides, like in a math problem) by 2 to get rid of the fraction.

Elana Weingord 1C
Posts: 34
Joined: Fri Apr 06, 2018 11:05 am

Re: Balancing equations with fractions

It might be easier to begin with the mole ratios in fractions, but the final answer must be given in whole numbers. Using whole numbers is important because when converting atoms needed etc. it is easiest to use whole numbers in the conversions.

Rummel Requerme 1E
Posts: 35
Joined: Fri Sep 25, 2015 3:00 am
Been upvoted: 1 time

Re: Balancing equations with fractions

It's bad style (actually, even looked down upon by scholars) to be leaving fractions in the equation. Multiply both sides by whatever number, in this case, the number 2, and leave whole numbers.

Jose Munoz 1D
Posts: 22
Joined: Tue Nov 14, 2017 3:00 am

Re: Balancing equations with fractions

You could leave it like that, however it would just make your life more difficult going forward, that best thing would be for there to be whole numbers.