that's perfectly fine if it's something like Ba2+ + SO42- --> BaSO4
if not, do you mean multiple reactions involving the transfer of electrons?
Because I really don't know if they'll mark you down for writing more equations, judging by comments on this thread
...but it literally said ONE in capitals. It shows that you haven't read the question if you use more, and it wouldn't be fair to other students who adhered to the question. If it didn't specify one I would've written at least 3
I think they actually can deduct marks, because it was a capitalised ONE. Like English, when they specify one related text I don't think it's smart to talk about two
That was in the anion testing dot point. For carbonate you add nitric acid and you produce CO2 gas as a product indicating the presence of carbonate ions. Sulfate you acidify the sample with HNO3 and add Ba(NO3)2, giving precipitate of BaSO4 and thereby indicating SO4- is present. For chloride...
The key thing (again), was not to identify the trend, but to show that it achieved the aim; hence at least partially valid. The validity was compromised by the heat losses and incorrect use of the thermometer.
Also multiple choice solutions (almost 100% sure these are correct):
1: D
2: A
3: B
4: C
5: C
6: B
7: C
8: C
9: A
10: C
11: A
12: C
13: B
14: D
15: D
16: B
17: A
18: D
19: B
20: D
Honestly I don't think you'd get more than 3 marks for just writing the variables. It shows a lack of knowledge in terms of what is meant by the term 'validity' if all you talk about is the variables of the experiment and how they are controlled/changes to identify the independent variable.
I'd...
Hmmm, okay. I was thinking that because of the difficulty level of this exam, that the normal raw mark of 92/93 needed to state rank would rise to something like 95. A mark of 97 raw would be quite exceptional, I highly doubt that would at least 20 students would score that high on any exam in...
Yes to get all 5 marks I'd certainly think that at least one of those would be allocated to writing at least one equation.
Personally, the only two I saw as necessary as was displayed in the experiment was the combustion of sulfur to form sulfur dioxide, as well as the hydration of sulfur...