HSC Chemistry SOLUTIONS / Thoughts / Predictions (4 Viewers)

[Xanthi]

Yeah, Learnable is a bit dodgy and I can see why the exam isn't too well made. I think it'd be better to just be doing past trials, hsc exams and the like.

Yeah I was going to start the physics one. But if it's drag n drop not just the quiz but the practice trial it might not be worth doing?

 

[Speed’o’sound Sonic]

Yeah I was going to start the physics one. But if it's drag n drop not just the quiz but the practice trial it might not be worth doing?

Honesty, I’m not gonna sit the physics one after the state of the Chem one today

 

[jazz519]

I just tried sitting the chemistry one - I don't really recommend it:
- wanted us to explain the NMR spectrum of aspirin (which is interesting, to say the least)
- all the extended responses are drag and drop, which makes it completely not worth doing
- multiple questions had incomplete stimulus data (e.g. a Hess' Law question was missing one of the molar enthalpy of formatoin)
- the typed number answers were worth 2-3 marks and you could only enter a single number, and there was no indication of how precise they wanted
- scrolling up and down to see the stimulus was a pain
Bit hard to explain without just showing the questions, but it was extremely wack.

Yeah I have had a brief look at the exams as well. They are okay but in terms of preparing you for HSC style questions not so much as you can't just drag and drop in the HSC.

 

[jazz519]

Oh God.. at most I know how the properties and uses for each but its literally a TRAVESTY when the question asks to draw polymers out and your given two reactants. omg and I suck at

The questions are not too complicated. If you have a good approach and spend time on a couple of questions you will see they become very repetitive

Addition polymers example:

1. Move all bonds not involved in double bond to the vertical position
2. Redraw the structure 3 times without double bond
3. Connect those 3 repeats together

Condensation polymers example:

This is the other way around but if you want to go from the two reactants to polymer
1. Remove 1 water from inside of the monomers and 1 water from outside of the monomers
2. Join together and put bracket and n

 

[Xanthi]

Oh God.. at most I know how the properties and uses for each but its literally a TRAVESTY when the question asks to draw polymers out and your given two reactants. omg and I suck at

Unfortunately the connection between structure, property and uses are problematic. For some polymers such as nylon, there is no generally agreed connection. It is hydrophilic but nylon is used because of its strength not ability to absorb water. There is no way to justify how it is stronger than other polymers based on structure, however.

 

[Speed’o’sound Sonic]

The questions are not too complicated. If you have a good approach and spend time on a couple of questions you will see they become very repetitive

Addition polymers example:
View attachment 29354
1. Move all bonds not involved in double bond to the vertical position
2. Redraw the structure 3 times without double bond
3. Connect those 3 repeats together

Condensation polymers example:
View attachment 29355
This is the other way around but if you want to go from the two reactants to polymer
1. Remove 1 water from inside of the monomers and 1 water from outside of the monomers
2. Join together and put bracket and n

Thankyou!!! Chemistry god

 

[bekind2003]

The questions are not too complicated. If you have a good approach and spend time on a couple of questions you will see they become very repetitive

Addition polymers example:
View attachment 29354
1. Move all bonds not involved in double bond to the vertical position
2. Redraw the structure 3 times without double bond
3. Connect those 3 repeats together

Condensation polymers example:
View attachment 29355
This is the other way around but if you want to go from the two reactants to polymer
1. Remove 1 water from inside of the monomers and 1 water from outside of the monomers
2. Join together and put bracket and n

omg hold up the steps for drawing addition polymers is so helpful thank you! Could you clarify the condensation polymers again? So when were drawing what is the water outside of the monomers? (sorry I'm slow)

 

[bekind2003]

Unfortunately the connection between structure, property and uses are problematic. For some polymers such as nylon, there is no generally agreed connection. It is hydrophilic but nylon is used because of its strength not ability to absorb water. There is no way to justify how it is stronger than other polymers based on structure, however.

ahh yeah its pretty useless then, but there's always a sneaky question about polymer properties in most trials which is annoying

 

[jazz519]

omg hold up the steps for drawing addition polymers is so helpful thank you! Could you clarify the condensation polymers again? So when were drawing what is the water outside of the monomers? (sorry I'm slow)

A condensation polymer forms via water being eliminated

This means if you want to draw from 2 monomers to a polymer we have to remove the water

Basically take off the OH on the left structure on both sides

Take off the H from the NH2 on the right structure on both sides

That in total means you are removing 2OH and 2H which is 2H2O

 

[bekind2003]

A condensation polymer forms via water being eliminated

This means if you want to draw from 2 monomers to a polymer we have to remove the water

Basically take off the OH on the left structure on both sides

Take off the H from the NH2 on the right structure on both sides

That in total means you are removing 2OH and 2H which is 2H2O

ohh omg THANKYOU legend

 

[darkgates]

Guys the syllabus says only precipitation titrations. Do we need to know Mohrs, Volhard's and Fajans method? If not can someone please list all the important titrations?

 

[Esdog07]

Guys the syllabus says only precipitation titrations. Do we need to know Mohrs, Volhard's and Fajans method? If not can someone please list all the important titrations?

I don't remember studying any of those methods in my class. Plus for all the trial and hsc exam papers I have done, I don't remember seeing any questions on those methods.

 

[MrGresh]

I don't remember studying any of those methods in my class. Plus for all the trial and hsc exam papers I have done, I don't remember seeing any questions on those methods.

Yeah we didnt do them either. Many exams include them, but walk you through them such that you do not need to actually know the methods beforehand.

I don't think it's in NESA's interests to include these titrations as it is essentially luck whether students know the methods. This being said, I think it's a safe choice to be familiar with them at least in terms of calculation.

We will see!

 

[MrGresh]

Hi lads and lasses,

when rounding up pH and pOH do u recommend rounding up to sig figs or decimal places? Because for the whole year my teacher has been telling us to round it up to one decimal places, but hsc Sample solutions suggest otherwise

Idk I've seen it done differently in different places. I'd go with NESA for obvious reasons

 

[Speed’o’sound Sonic]

Let’s gooo lads. Final exam preparation, now that physics is out of the way it’s Chem Chem Chem! how are we all feeling so far? How’s everyone doing

 

[Xanthi]

It's the race to the end!

Revising hydrocarbons though

 

[Speed’o’sound Sonic]

It's the race to the end!

Revising hydrocarbons though

It’s you again I swear you’ve been on all of them, maths ext2 and physics as well?
yeah early mod 7 is a bit of a weak spot for me too. Obviously mod5 and 6 are breezy but 7 and 8 are a bit harder

 

[Xanthi]

It’s you again I swear you’ve been on all of them, maths ext2 and physics as well?
yeah early mod 7 is a bit of a weak spot for me too. Obviously mod5 and 6 are breezy but 7 and 8 are a bit harder

You've been here for all of them too!

 

[Speed’o’sound Sonic]

You've been here for all of them too!

Yep! Mad respect man. What course u going for?

 

[Xanthi]

Yep! Mad respect man. What course u going for?

Engi type stuff

But I'm indecisive, so that might change.