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# Balancing Equations. Tweet

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1. Balancing Equations.
(Original post by charco)
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Quoted charco as he helped me last time regarding a markscheme situation.

In a markscheme an answer to a balanced equation is:

4NH3 + 302 --> 2N2 + 6H20

However I put

2NH3 + 1 1/2 02 --> N2 + 3H20

Usually they say 'OR multiples' or something to that effect in the markscheme, however it doesnt say that here, neither is it in the reject column.

Is this correct/incorrect?
2. Re: Balancing Equations.
(Original post by EffKayy)
Quoted charco as he helped me last time regarding a markscheme situation.

In a markscheme an answer to a balanced equation is:

4NH3 + 302 --> 2N2 + 6H20

However I put

2NH3 + 1 1/2 02 --> N2 + 3H20

Usually they say 'OR multiples' or something to that effect in the markscheme, however it doesnt say that here, neither is it in the reject column.

Is this correct/incorrect?
What you have written is not actually incorrect as you have the right proportions of each element/compound. But it is usually best to avoid ending up with fractions in your equation as mark schemes usually prefer whole numbers of things. So in your equation, if you just multiply through by 2 you get rid of the 1.5
3. Re: Balancing Equations.
(Original post by EffKayy)
Quoted charco as he helped me last time regarding a markscheme situation.

In a markscheme an answer to a balanced equation is:

4NH3 + 302 --> 2N2 + 6H20

However I put

2NH3 + 1 1/2 02 --> N2 + 3H20

Usually they say 'OR multiples' or something to that effect in the markscheme, however it doesnt say that here, neither is it in the reject column.

Is this correct/incorrect?
It should be allowed unless the question stated to use integers. Also, it would have been better to write the 1 1/2 as 3/2. Anyway, I don't see why they would reject it, mark schemes don't contain every piece of information for the examiner.
4. Re: Balancing Equations.
(Original post by NutterFrutter)
It should be allowed unless the question stated to use integers. Also, it would have been better to write the 1 1/2 as 3/2. Anyway, I don't see why they would reject it, mark schemes don't contain every piece of information for the examiner.
I agree. They shouldn't mark it wrong.