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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?
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.
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.
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 .
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.
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.
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.
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.
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