Chemistry: Discussion, Questions & Potential Solutions

[billy606]

Possible for someone to upload a copy of the exam, please?

mods are gonna get ya

[sweetiepi]

Possible for someone to upload a copy of the exam, please?

Your answer is this, sorry!

[jyce]

mods are gonna get ya

Your answer is this, sorry!

Hmm, I guess things have changed since I was last active on these forums - thanks!

[Purple_Mango]

I... I thought I did pretty well on the exam, since I felt happy afterwards, but reading some answers on here made me think otherwise. 
Anyway, just going to list some questions I had some trouble with;
A systematic error for the electrical calibration? I wrote that the voltage applied would not be exactly as the expected value of 6.0V (but on second thought, that's a random error, isn't it?)
I wasn't sure what limitation was apparent in the chemical calibration, so I just said that bc chemical calibration was conducted immediately afterwards the electrical calibration, change in temperature may be affected.
Also, how do you explain the coenzyme question (how vitamin C interacts physically and chemically with the enzyme to assist in the catalysis of collagen(?))? I assumed you had to include the amino acid that was drawn in part a.) in the answer... but I don't know.
Lastly, before I disappear, that coconut question. Did you have to draw a triglyceride, since it said "show the structure of a triglyceride"? It was strange drawing it with lines running across the page.
tl;dr (sorry)

[vector_graphics]

A systematic error for the electrical calibration? I wrote that the voltage applied would not be exactly as the expected value of 6.0V (but on second thought, that's a random error, isn't it?)

the thing is, your answer can be both random and systematic, it is random if you explain it in the context of voltage fluctuations but is systematic if you explain it in terms of resistance of electrical equipment. it depends what context it is in.

[jimbo1212]

Stay tuned - they'll be done by this evening
they said ....

[G-Fr3sh]

11.375% =11%

I calculated 11.4% but its wrong, cuz it ask for percentage of mass from cellulose so its 34%

[Lear]

Stay tuned - they'll be done by this evening
they said ....

The day isn't over. Remember they are quite generously doing this for free with no strings attached. The least we can do to show our appreciation for their altruistic efforts is be patient.

[matthewmwps]

The day isn't over. Remember they are quite generously doing this for free with no strings attached. The least we can do to show our appreciation for their altruistic efforts is be patient.

Also, the chemistry exam is WAY more open-ended with its answers than methods and specialist. It'd probably take ages to find of every possible answer for some of the theory questions

[AlphaZero]

Hey all. Sorry the solutions are taking a long time. The chem exam is massive and there's just a lot to cover. Tonight, we're just going to upload the Section B full answers. We'll provide the answers to Section A, but with no working or explanation. We'll slowly add full solutions for Section A in the next few days. (We're incredibly busy at the moment!)

[addictwithatextbook]

I thought it was 2-methyl propan-1-amine as there were 3 carbon environments present, 2-methylpropan-2-amine only has 2. Looks like this

Will you lose the mark if you expanded the NH2 bonds? The data book shows the O-H bond extended but I'm not sure if it only applies to O-H bonds.

[AlphaZero]

Solutions are up!

Get them here: https://atarnotes.com/forum/index.php?topic=181372.msg1085659#msg1085659

Or get them on our website: twmpublications.com/solutions

[Synchronised123]

Ended up getting 108-110, am i that bloody stupid for making the stupidest of mistakes by not timing (x4) for the solar panels, not taking into factor the 35% efficiency, saying succinic acid instead of glycerol.... ffs

[Synchronised123]

Solutions are up!

Get them here: https://atarnotes.com/forum/index.php?topic=181372.msg1085659#msg1085659

Or get them on our website: twmpublications.com/solutions

thanks for your hard work, i appreciate your generosity

[Sci-hopeful]

Solutions are up!

Get them here: https://atarnotes.com/forum/index.php?topic=181372.msg1085659#msg1085659

Or get them on our website: twmpublications.com/solutions

WOW!!! Thank you so much! Truly amazing work - would have taken AGES to type up chemical structures!

Friendly FYI (zero disrespect, as your work is much appreciated)

1aiii is 2,3 dibromo 4-methyl hexane

2d Oxygen is evolved (not hydrogen)

3bi M(parent) = 73g/mol

5cii m(ethanol) = 11370g, which in then times by 29.6KJ/g (databook)

8cii n(petrodiesel) has not been inputted into the calculator correctly, affecting subsequent working out

9d Both experiments were turned off after 180 sec (identical graphs) to this point. Maybe a stirring issue between Student A and B???