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General Thoughts: Chemistry (3 Viewers)

bhatman

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Also what are people expecting for a state rank raw mark? Also what kind of raw is expected to achieve an external mark of 95+?
 

enigma_1

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You should say the validity of the experiment is moderate:
Seeing as though the aim was to determine a quantitative relationship between the alkanol used and the heat of combustion, the student effectively achieved this. However, the accuracy of the data is highly compromised to the release of heat from the spirit burner to the surroundings, inability of the beaker and gauze mat to transfer all of the heat to the water (affecting temperature change as it would take longer), as well the the thermometer being placed on the glass and not in the centre of the liquid. But the first sentence is pivotal because it keeps to the aim of the experiment.
Did we have to give equations for acid rain?
 

enigma_1

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Also what are people expecting for a state rank raw mark? Also what kind of raw is expected to achieve an external mark of 95+?
90+ raw for 95 and above usually

state rank is >92/93 raw
 

bhatman

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Did we have to give equations for acid rain?
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 dioxide to form sulfurous acid. I didn't put in the oxidation of sulfurous acid to sulfuric acid, however this would be perfectly fine too.
 

IR

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You should say the validity of the experiment is moderate:
Seeing as though the aim was to determine a quantitative relationship between the alkanol used and the heat of combustion, the student effectively achieved this. However, the accuracy of the data is highly compromised to the release of heat from the spirit burner to the surroundings, inability of the beaker and gauze mat to transfer all of the heat to the water (affecting temperature change as it would take longer), as well the the thermometer being placed on the glass and not in the centre of the liquid. But the first sentence is pivotal because it keeps to the aim of the experiment.
Thanks. Oh ok so how much?
 

bhatman

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State rank - 97+ raw
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 chemistry, let alone the HSC.
 
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I didn't finish 3 marks mate, plus I tried to do the whole multiple choice in like 8 minutes, thus getting only 17/20.

Thats 6 marks lost. Plus chem marking is freaking *****

Hoping so bad for like 85-88 raw :( I seriously messed up.
What 3 marks?

dw you'll do well :D

3u tomorrow
 

bhatman

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Oh and I wrote all the variables and showed the controlled variables.
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 think that you have to show the effect of the variables on the data achieved to get a 4 or 5, and the key thing to take from the question was that despite the fact the data was a good 15% off the theoretical value for most of the readings, it displayed a general quantitative trend that with the increasing number of carbon atoms in the alkanol the heat of combustion per mole increased in a linear trend.
 

SuchSmallHands

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omg what did you write lol

I think I only had time to write "zinc could get oxidised by air" (strong bs/10) which is equivalent to not answering the question
I didn't have much time to do chem of art (left myself 30 minutes whyyy) and I didn't know much about the prac. The question on problems with it? God I had nothing. I said the positive pressure from the hydrogen escaping through the cotton wool might not be enough to exclude oxygen and I also said that the zinc might be impure. I have no idea what they actually wanted for that, holy shit.
 
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chem of art :/ 3 WHOLE MARKS

yeah... so keen. sarcasm.

Everyone seems to have either found it really easy or like ambiguous-hard. How did you find it?
The paper wasn't hard, relatively easy in comparison to other HSC papers.

However, what I am scared of is this chemistry marking criteria! It's going to be so harsh.
 

IR

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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 think that you have to show the effect of the variables on the data achieved to get a 4 or 5, and the key thing to take from the question was that despite the fact the data was a good 15% off the theoretical value for most of the readings, it displayed a general quantitative trend that with the increasing number of carbon atoms in the alkanol the heat of combustion per mole increased in a linear trend.
Yeh i wrote it was parallel and linear trend since controlled just inaccurate.
 

hecticated

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I think I screwed up both 7 markers (wtf was the shipwreck one) but I'm hoping for 75+ but a mark in the 80s would me more fabulous.
3U tomorrow and after that I can spam the play button on League of Legends wooo
 

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