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GCSE Chemistry: Question about marking

Do you get the 'correct balancing' mark even if the products of the chemical equation are slightly wrong?

I wrote 2 NH3 + H2SO4 --> (NH4)2SO4 + H2, and the question was worth 2 marks.
I know I accidentally added the unnecessary "+ H2" at the end, so I definitely cannot get the mark for correct formula, but can't I at least get one mark for correct balancing, because I wrote '2' in front of 'NH3'?
I would say it would be error carried forward
Original post by SauronKing
Do you get the 'correct balancing' mark even if the products of the chemical equation are slightly wrong?

I wrote 2 NH3 + H2SO4 --> (NH4)2SO4 + H2, and the question was worth 2 marks.
I know I accidentally added the unnecessary "+ H2" at the end, so I definitely cannot get the mark for correct formula, but can't I at least get one mark for correct balancing, because I wrote '2' in front of 'NH3'?
Reply 2
Original post by aliciaej
I would say it would be error carried forward


What do you mean? does this mean that I get zero marks? Or 1/2 mark?
Original post by SauronKing
Do you get the 'correct balancing' mark even if the products of the chemical equation are slightly wrong?

I wrote 2 NH3 + H2SO4 --> (NH4)2SO4 + H2, and the question was worth 2 marks.
I know I accidentally added the unnecessary "+ H2" at the end, so I definitely cannot get the mark for correct formula, but can't I at least get one mark for correct balancing, because I wrote '2' in front of 'NH3'?


I imagine it would lose both marks, as the equation isn’t balanced. Count the hydrogens on each side of the equation.
Reply 4
Original post by TypicalNerd
I imagine it would lose both marks, as the equation isn’t balanced. Count the hydrogens on each side of the equation.


Well, don't you think that would be way too critical? Apart from the "+H2" part at the end, everything else is correct. If just adding this minor part really deducts all the marks, then this would be way too ruthless. Yes, the equation is not balanced, but how is anyone then supposed to get any of the marks then? Is the balancing mark really so dependent on the formula mark? I mean, OK then, what if a student writes a completely irrelevant chemical equation completely unrelated to the question, e.g. C6H12O6 + 6O2 --> 6C2O + 6H2O. Does he/she still get one mark just because of ecf, due to the equation being balanced?! When the question asks for the chemical formula representing the reaction between ammonia and sulfuric acid, the students only writes the chemical formula for respiration instead (for whatever reason) and yet, still gets one mark for correct balancing. This does not really make sense...

Perhaps the balancing mark is not awarded by ecf, but only given when the student writes the expected number (e.g. 2) in front of the expected reactant or product (e.g. NH3), i.e. the correct balancing number for what would be the correct equation.

What do you think?
(edited 1 year ago)
Original post by SauronKing
Well, don't you think that would be way too critical? Apart from the "+H2" part at the end, everything else is correct. If just adding this minor part really deducts all the marks, then this would be way too ruthless. Yes, the equation is not balanced, but how is anyone then supposed to get any of the marks then? Is the balancing mark really so dependent on the formula mark? I mean, OK then, what if a student writes a completely irrelevant chemical equation completely unrelated to the question, e.g. C6H12O6 + 6O2 --> 6C2O + 6H2O. Does he/she still get one mark just because of ecf, due to the equation being balanced?! When the question asks for the chemical formula representing the reaction between ammonia and sulfuric acid, the students only writes the chemical formula for respiration instead (for whatever reason) and yet, still gets one mark for correct balancing. This does not really make sense...

Perhaps the balancing mark is not awarded by ecf, but only given when the student writes the expected number (e.g. 2) in front of the expected reactant or product (e.g. NH3), i.e. the correct balancing number for what would be the correct equation.

What do you think?


It’s harsh, but remember that when your real exams are marked, they will be marked very harshly.

You may get the correct formulae mark (assuming that the correct formulae mark is awarded for seeing NH3, H2SO4 and (NH4)2SO4), but you’ve definitely lost the balancing mark.

If you wrote an irrelevant equation, I doubt you’d get any marks whatsoever, because balancing marks are usually dependent on having the correct formulae if memory serves.

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