HSC Chemistry Exam Solutions / Thoughts (4 Viewers)

[flowerp]

You will probably be fine. I doubt they are thinking that hard about real life application in HSC, otherwise half the stuff would be wrong lol

Hopefully !!!!

 

[Arrowshaft]

You reckon its possible for the paper to leak considering how the exam booklets are personalised? Ik it happened for bio

 

[AHafza]

Mmm good question

 

[worldno17]

You reckon its possible for the paper to leak considering how the exam booklets are personalised? Ik it happened for bio

Hmm the exam paper was uploaded by NESA 2 days after bio ended. So i think the wait won't be too long anyway.

 

[Arrowshaft]

Same! I expressed it as positive though - thought molar heat of combustion is usually expressed positive as a convention?

Is it?

 

[dotwingz]

You reckon its possible for the paper to leak considering how the exam booklets are personalised? Ik it happened for bio

Economics is also personalised but that was uploaded very quickly

 

[jazz519]

You reckon its possible for the paper to leak considering how the exam booklets are personalised? Ik it happened for bio

Doubt it only way to get it is if a teacher leaks it but I don't think any of them would freely release it to everyone because they probably get some backlash from NESA if they find out

But yeah even if it comes out in 2 days I will for sure write out solutions regardless

 

[worldno17]

Is it?

Mhm, I believe so.

 

[Arrowshaft]

Mhm, I believe so.

I thought delta h is always negative

 

[worldno17]

I thought delta h is always negative

It's a convention to express delta Hc as positive but I don't think it matters much.

 

[jazz519]

Is it?

Sometimes people write negative, sometimes not honestly doesn't matter. Why people sometimes tend to write molar heat of combustion as positive is because the definition states that it is the amount of heat released per mole of fuel burnt at 25 degrees Celsius and 1 atm. But I have also seen in other exams they have put -ve because it is exothermic. I wouldn't worry too much

 

[Arrowshaft]

Sometimes people write negative, sometimes not honestly doesn't matter. Why people sometimes tend to write molar heat of combustion as positive is because the definition states that it is the amount of heat released per mole of fuel burnt at 25 degrees Celsius and 1 atm. But I have also seen in other exams they have put -ve because it is exothermic. I wouldn't worry too much

Ok thanks, because my teacher penalised me once for missing the negative so i was confused

 

[englishessayssuck]

sup people
for the aluminium hydroxide question, could we just assume the thing just dissociates completely into al3+ and OH-, because there's like no ksp value?
also for the oxidation you could literally just put acidified dichromate which should turn the orange Cr2O7(2-) into green Cr(3+)

 

[dcosmo]

DeltaH is always negative as combustion is an exothermic reaction....

 

[CarbonMini]

Guys for the question that asked for an explanation of the titration curve, the one with the conductometric graph already given, did you guys talk about the above conductometric graph or the actual titration curve like me? I think im wrong

Edit: and also, you dont need to get a raw mark over 90 to get band 6???

 

[worldno17]

Guys for the question that asked for an explanation of the titration curve, the one with the conductometric graph already given, did you guys talk about the above conductometric graph or the actual titration curve like me? I think im wrong

Edit: and also, you dont need to get a raw mark over 90 to get band 6???

I talked about the conductometric curve (since it's called a conductometric titration).
And no, you don't. Above 90 raw gets close to 93-5+? Cmiiw.

 

[Arrowshaft]

Guys for the question that asked for an explanation of the titration curve, the one with the conductometric graph already given, did you guys talk about the above conductometric graph or the actual titration curve like me? I think im wrong

Edit: and also, you dont need to get a raw mark over 90 to get band 6???

I think it meant the conductometric curve. Seems random to just ask to explain the pH titration curve. Also, the conductometric curve is also a titration curve as the titration is called conductometric titration

 

[Arrowshaft]

Guys for the question that asked for an explanation of the titration curve, the one with the conductometric graph already given, did you guys talk about the above conductometric graph or the actual titration curve like me? I think im wrong

Edit: and also, you dont need to get a raw mark over 90 to get band 6???

That’s aligned, we mean raw

 

[englishessayssuck]

Guys for the question that asked for an explanation of the titration curve, the one with the conductometric graph already given, did you guys talk about the above conductometric graph or the actual titration curve like me? I think im wrong

Edit: and also, you dont need to get a raw mark over 90 to get band 6???

like ideally you would talk about both, like defining why the conductometric titration occurs (due to moving mobile charges etc) and explain why it's the shape it is (like u have ions in solution at first making good conductivity, then reduces due to neutralisation of hydronium and hydroxide, then goes up due to excess h+ and cl-)

 

[Arrowshaft]

like ideally you would talk about both, like defining why the conductometric titration occurs (due to moving mobile charges etc) and explain why it's the shape it is (like u have ions in solution at first making good conductivity, then reduces due to neutralisation of hydronium and hydroxide, then goes up due to excess h+ and cl-)

Cl- doesnt contribute much tho, its less mobile and a lot heavier