General thoughts: HSC chemistry 2015 (1 Viewer)

[Crisium]

no way. I learnt solvay process in the 20 minutes before i went in to the exam.
Was lucky the questions were easy for that

LOL

Yeah I memorised it in the morning as well and was kind of hoping for it to be the 7 marker though

 

[HecticLad]

Gotta go get a band 6 in physics now... fuck.

Ever since i stuffed up 2u math (think i got 93/94 raw) --> was thinking of getting like 97 aligned before the 2u exam (like in past HSC papers when i compared my raw mark), but now it will only be like 95 aligned. (BTW i changed my math predictions in my sig. after the exam).

Then i said i was gonna get band 6 today but nup. Stupid mistakes like not labelling axis on the graph etc.. are gonna cost me.

.

at least i have 3.5 days to rote learn all the theory dot points in physics (am comfortble with the understanding and calculation qustions)

>mfw 8 mark question on einstein and planck and their views on whether science is removed from political and social factors

 

[Mr_Kap]

Conquering chem textbook had a mad part on the fertiliser experiment, i wrote slowly adding the BaCl to a heated solution of the dissolved fertiliser will produce larger precipitate crystals, this means that there will be less precipitate lost through the filter, also less ions from the solution will adsorb onto the precipitate crystals due to less surface area so it would be closer to the real value, also wrote that the solution should be cooled in an ice bath after precipitation to reduce the solubility of BaSO4, and finally rinsing the filtrate with 4 lots of 5ml water will remove and contaminants on the surface of BaSO4 without compromising solubilty, and then rinsing with 5ml ethanol to aid in the drying process

I answered that question like a 5/6 marker in the amount i wrote. I did a whole assignment on that prac where i had to write a beast method justifying every step, and how to increase validity/accuraccy/reliability so when last night i went over it, and when i saw the students method i was like WTF is this? This is a fucked up method, so it was easy for me to fix it

 

[Crisium]

Gotta go get a band 6 in physics now... fuck.

Ever since i stuffed up 2u math (think i got 93/94 raw) --> was thinking of getting like 97 aligned before the 2u exam (like in past HSC papers when i compared my raw mark), but now it will only be like 95 aligned. (BTW i changed my math predictions in my sig. after the exam).

Then i said i was gonna get band 6 today but nup. Stupid mistakes like not labelling axis on the graph etc.. are gonna cost me.

.

at least i have 3.5 days to rote learn all the theory dot points in physics (am comfortble with the understanding and calculation qustions)

You'll be fine

Just keep in mind that band 6'ing physics is not an easy task

 

[Ekman]

LOL

Yeah I memorised it in the morning as well and was kind of hoping for it to be the 7 marker though

Lol I actually quickly went through the method of producing soap in a school laboratory like 1 hour before the exam.

 

[aanthnnyyy]

NAOH concentration 0.02 M ? Or something along those lines :/?

 

[diladial]

Haha I'm probably the only one, but I did Biochem and it was brilliant. Other than 1 question about models, I might have aced it. (Biochem that is. Not the whole test)

Also, just because I like to crush dreams? Who put the answer to 10 as D? The incomplete combustion one?
The answer was A, although they did trick me at first.

Also I got 0.180 or 0.181 I cant remember for the NaOH and 46.something% for the sulphate.

The line graph was just connect the dots right?

Oh and what was the answer to 17? I put C since it was near an ocean and should have high dissolved solids, but it really depends on the tide whether it has high or low turbidity so Idk...

Also, would be interesting to hear what people answered in 24b, the Sulphate one, about how to improve it.

Good luck lads and ladesses.

P.S Im expecting/hoping for a raw mark of 88, anyone know what that aligns to? I hope it's a band 6.

wait how is the incomplete combustion one D??? was it balanced??

 

[Mr_Kap]

LOL

Yeah I memorised it in the morning as well and was kind of hoping for it to be the 7 marker though

Nah no way. I didn't even know ANYTHING about the solvay process before 20 minutes before the exam though. I didn't even know what it produced.
Was lucky i quickly rote learned all the equations and the shit from AHmads notes.

 

[Mr_Kap]

Wait. Think i made calculation error in the NaOH. I don't remember the answer being so 'neat' as 0.2 mol/L.

It might have been i cant remember what asnwer i wrote, i was doing it so fast. I did the right method so im confident if that was the answer that i wrote it,

3NaOH is needed to react with one mole of citric acid yeh???

 

[iStudent]

So what do you think about aligning... Better than last year?

Anything should align better than last year... The aligning last year was just horrible :/ (unless the general trend is easier exams/easier marking)

 

[SlimiJay]

Wait. Think i made calculation error in the NaOH. I don't remember the answer being so 'neat' as 0.2 mol/L.

It might have been i cant remember what asnwer i wrote, i was doing it so fast. I did the right method so im confident if that was the answer that i wrote it,

3NaOH is needed to react with one mole of citric acid yeh???

why was it 3NaOH?? i think i balanced wrong

 

[HecticLad]

why was it 3NaOH?? i think i balanced wrong

citric is triprotic fam

 

[sida1049]

On second thought, the answer could be taking it from the same site, if we assume that the only purpose of the experiment is to measure contamination of lead ions on one pond. The only reason why I went with my reasoning is because of the word 'contamination site', meaning that the purpose of the experiment is to measure the impacts of the contamination site on ponds.

I originally had your thought process, in thinking that reliability would be maximised by taking samples from multiple ponds... until I realised that upon closer inspection, nothing in the question actually says that they were testing for pollution (which was something most students, including myself, initially assumed), but rather the concentration of lead ions in that specific pond.

 

[Catz]

Is an 80 raw going to get me a high band 5?

 

[SlimiJay]

citric is triprotic fam

ohh shit forgot about that
how many marks do i lose if method was all right?

 

[nerdz1]

why was it 3NaOH?? i think i balanced wrong

Citric acid is a triprotic acid.

 

[Crisium]

Lol I actually quickly went through the method of producing soap in a school laboratory like 1 hour before the exam.

Haha what did you put in terms of safety?

I mentioned using a hot plate so you can moderate the temperature more easily than with a bunsen burner - This prevents the mixture from over-flowing (this became a real nuisance during our irl prac) and spitting hot liquid everywhere (also wearing safety goggles.

washing the soap product multiple times with water to ensure that no caustic sodium hydroxide remains on the soap - Prevents burns/irritation to the skin, etc.

Neutralising the left over aqueous solution before its disposal

and I mentioned a few more

 

[Librah]

Is an 80 raw going to get me a high band 5?

Probably, might give b6 depending on the exam difficulty, but i haven't seen it, so i can't really comment on that.

 

[Catz]

Probably, might give b6 depending on the exam difficulty, but i haven't seen it, so i can't really comment on that.

Lol i would die if I get a band 6 for chem haha

 

[Catz]

What did youse do for that arrhenius and bronsted question?