General thoughts: HSC chemistry 2015 (1 Viewer)

[HecticLad]

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

was out of 4 wasnt it? id say if you wrote our all your formulas and showed the substitution and all your calculations were correct with the formula you used, youd probably get 2, maybe 3 if youre lucky

 

[band6man]

Hey buds anyone remember the question with acetic acid being added to sodium acetate and then NaOH being added to that. Was the answer that the pH doesn't change? I wasn't sure tbh.

 

[nancylime]

what was the trend line supposed to be for the graph? line of best fit or join the dots?

 

[SlimiJay]

Hey buds anyone remember the question with acetic acid being added to sodium acetate and then NaOH being added to that. Was the answer that the pH doesn't change? I wasn't sure tbh.

yeah i wrote about how CH3COO- is a buffer system and will resist a change in pH

 

[Mr_Kap]

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

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

Nah it was an easy test. Only hard thing is if you haven't studied one of those battery things (like button cell etc..) as there was a 4 marker on it. I tried as best as i could and it seemed good enough for three marks but i'm thinking 2 marks just in case.

I found it easier than last years test but other people found it harder, but overall i think aligning will be around the same as last year.

 

[SlimiJay]

what was the trend line supposed to be for the graph? line of best fit or join the dots?

https://www.google.com.au/search?q=...ved=0CAYQ_AUoAWoVChMIoZ7cu-DXyAIVZFumCh15YgcU

 

[nancylime]

https://www.google.com.au/search?q=...ved=0CAYQ_AUoAWoVChMIoZ7cu-DXyAIVZFumCh15YgcU

ah that's a killer

 

[Crisium]

Hey buds anyone remember the question with acetic acid being added to sodium acetate and then NaOH being added to that. Was the answer that the pH doesn't change? I wasn't sure tbh.

Yeah because it forms a buffer system

They also used terms to kind of hint at it

Like "equal volume and concentration" and a "small amount of sodium hydroxide being added"

 

[band6man]

yeah i wrote about how CH3COO- is a buffer system and will resist a change in pH

Same band 6 so easy for me then

 

[Catz]

Nah it was an easy test. Only hard thing is if you haven't studied one of those battery things (like button cell etc..) as there was a 4 marker on it. I tried as best as i could and it seemed good enough for three marks but i'm thinking 2 marks just in case.

I found it easier than last years test but other people found it harder, but overall i think aligning will be around the same as last year.

I'm hoping not lol last year aligning was horrible

 

[Mr_Kap]

Yeah because it forms a buffer system

They also used terms to kind of hint at it

Like "equal volume and concentration" and a "small amount of sodium hydroxide being added"

shit. Im pretty sure i read the question wrong. Oh well, that's 3/5 "safety" marks accounted for

 

[Catz]

How many marks was the buffer question?

 

[TQuadded]

Holy shit. I'm looking through and I saw everyone talking about the citric acid thing. I don't remember at all doing a concentration calculation. Was that on the page next to it on the right side?

 

[band6man]

How many marks was the buffer question?

3

 

[Mr_Kap]

I'm hoping not lol last year aligning was horrible

wasnt THAT bad ---> actually on second thought it was pretty bad. a weighted RAW mark of 77 went to 86 aligned.

I know that compared to other years its pretty atrocious but its still something i guess.

 

[Hazabot]

Oh, with the 5 mark radioisotope question, what would the marking guidelines for that be?
I had a good understanding of Americium 241, but I just don't see how they could pull 5 marks out of any answer...

 

[Catz]

wasnt THAT bad ---> actually on second thought it was pretty bad. a weighted RAW mark of 77 went to 86 aligned.

I know that compared to other years its pretty atrocious but its still something i guess.

To an extent I guess

 

[nancylime]

Oh, with the 5 mark radioisotope question, what would the marking guidelines for that be?
I had a good understanding of Americium 241, but I just don't see how they could pull 5 marks out of any answer...

yeah tru I feel like the whole paper was awarding stacks of marks for questions that in the past would be worth only 2 or 3, like I felt that the baso4 and titration calculations were generous and well as the radioisotope

 

[HecticLad]

Holy shit. I'm looking through and I saw everyone talking about the citric acid thing. I don't remember at all doing a concentration calculation. Was that on the page next to it on the right side?

yeah i think it might have been, for some reason i remember the question being on its own page, although if that is true i cant remember what was below the one where you had to draw the structure of citric

 

[nancylime]

yeah i think it might have been, for some reason i remember the question being on its own page, although if that is true i cant remember what was below the one where you had to draw the structure of citric

yeah it was on the next page