HSC Chemistry: Suggested Answers and Discussion

[BellaG11111]

Just wondering for industrial Chem if you could have talked about dilute NaCl as it was not specified whether or not concentrated was used in the experiment ?

[karenc.]

Just wondering for industrial Chem if you could have talked about dilute NaCl as it was not specified whether or not concentrated was used in the experiment ?

Yeah you could have. In my school we did both dilute and concentrated.

[jazz519]

Hey for the ic calculation shouldn't it be c=n/v = 0.0328/3 = 0.01093333...M and then K = [h2s] [nh3] = (0.010933333...)^2 = 1.1953777 x 10^-4

[RuiAce]

Just wondering for industrial Chem if you could have talked about dilute NaCl as it was not specified whether or not concentrated was used in the experiment ?

Yeah that's fine. I don't see it necessary as electrolysis of dilute NaCl solution is just electrolysis of water but I don't see it as penalisable

Hey for the ic calculation shouldn't it be c=n/v = 0.0328/3 = 0.01093333...M and then K = [h2s] [nh3] = (0.010933333...)^2 = 1.1953777 x 10^-4

Sorry cheers, wrong volume. Stared at the wrong number

[karenc.]

Hey for the ic calculation shouldn't it be c=n/v = 0.0328/3 = 0.01093333...M and then K = [h2s] [nh3] = (0.010933333...)^2 = 1.1953777 x 10^-4

i got that as well.

[karenc.]

Did you guys think the 7 marker was easier than previous years? cos i think it was almost like a 'brain dump' where you just had to talk about cfcs and their replacements and ozone destruction.

[RuiAce]

So whats the verdict? A or B?

We've decided A.

[RuiAce]

Did you guys think the 7 marker was easier than previous years? cos i think it was almost like a 'brain dump' where you just had to talk about cfcs and their replacements and ozone destruction.

Brain dumps are just boring.

[karenc.]

Brain dumps are just boring.

i was expecting the 7 marker to  be so much harder. I just love it how they give you 3 marks for drawing a graph.

[RuiAce]

i was expecting the 7 marker to  be so much harder. I just love it how they give you 3 marks for drawing a graph.

I for one hated brain dumps. I found memorisation the most boring of things in the course (especially water quality). The only thing that I was good at brain dumping was acid-base theories.

I guess with the graph they're gonna mark you on how well your line of best fit is and what not as well, and of course your headings and axis labels etc. But yeah pretty funny how it's 3 marks

[karenc.]

I for one hated brain dumps. I found memorisation the most boring of things in the course (especially water quality). The only thing that I was good at brain dumping was acid-base theories.

I guess with the graph they're gonna mark you on how well your line of best fit is and what not as well, and of course your headings and axis labels etc. But yeah pretty funny how it's 3 marks

Lol i am the opposite hehe I just rote learned my way through HSC chem.
Good thing this was so much more easier than our catholic schools trials paper

[Zyzyzyzy]

Isn't 21 Cu+? Because it's Cu(NO3)2

[queueq]

lol I included the NH4HS in the calculation... didn't see it was solid. How many marks would I lose? Did everything else correct.

[jakesilove]

Isn't 21 Cu+? Because it's Cu(NO3)2

NO3 has a charge of 1-, so two of them will have a charge of 2-. Thus, the Copper must have a charge of 2+ to create an overall neutral molecule

However, the Ag^(2+) should be Ag^(+)!

[RuiAce]

lol I included the NH4HS in the calculation... didn't see it was solid. How many marks would I lose? Did everything else correct.

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