• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

CSSA chemistry (2 Viewers)

zxreth

Member
Joined
Oct 11, 2009
Messages
775
Gender
Male
HSC
2011
Re: CSSA Chemistry 2011

Im the only one in my school doing chem (i do it via online so when you take the people from the other school in account its probs 15), only have 9 peolpe in year 12...
lol wtf
 
Joined
Feb 6, 2011
Messages
99
Location
Port Macquarie
Gender
Female
HSC
2011
Re: CSSA Chemistry 2011

Yup, the thing is i do bio and chem online and the school which hosts that is ranked about 300, so i have a combo
 

RANK 1

Active Member
Joined
Mar 16, 2011
Messages
1,369
Location
the hyperplane
Gender
Male
HSC
2011
Re: CSSA Chemistry 2011

our school is ranked 98 but thats only cos last years yr 12 were godlike
 

Joy_2575

Member
Joined
Jun 30, 2011
Messages
126
Gender
Female
HSC
N/A
CSSA Chem 2011

My school doesn't use CSSA papers for Chem, Maths , Physics and ancient history..

however I am curious to know what was in the paper? obviously bcs it is considered one of the harder papers

any particular questions that were not the normal typical HSC questions? Please do share

Thanks in Advance
 

jamesfirst

Active Member
Joined
Jan 30, 2010
Messages
2,005
Gender
Male
HSC
2011
I fucking wrote carbon. Fucking hell if that's actually write I will cry from happiness.
It is actually right, but the syllabus only talks about Sulfur and nitrogen oxides... so Idk


maybe if your teacher was generous, he'll give you a mark.
 

jamesfirst

Active Member
Joined
Jan 30, 2010
Messages
2,005
Gender
Male
HSC
2011
Re: CSSA Chemistry 2011

And.. WOW 3 pages!! on a 5 marker .. I wrote through the whole pages and then half another.

I did a similar thing to Midnight however was not as specific with the various changes in equilibrium.
How can you write 3 pages?? When the space for your answer is allocated ?


I myself filled the whole thing. I just talked about Haber process, him helping the german movement, and the knowledge of equilibrium enhancing ...
 

Askanison

New Member
Joined
Jan 1, 2009
Messages
4
Gender
Male
HSC
2011
Re: CSSA Chemistry 2011

even though im over thinking this... i need a second opinion.
for the Ba(OH)2 and HCl question heres what i did

25mL of 0.75 mol/l HCl
10mL of 0.5 mol/l Ba(OH)2

when added
==> (0.75)(0.025)=(0.035)x ==> x= 0.5357 mol/l of HCl [new concentration] 0.0187 moles of HCl present in total
==> (0.5)(0.01)=(0.035)y ==> y= 0.142857 mol/l of Ba(OH)2 [new concentration] 0.005 moles of Ba(OH)2 present in total

2HCl + Ba(OH)2 ----> BaCl2 + 2H2O
2 : 1 1 : 2

for the neutralization to occur... the double the amount of Moles of Ba(OH)2 is needed for HCl.
2HCl + Ba(OH)2 ----> BaCl2 + 2H2O
0.01 0.005

in total there are 0.0187 moles of HCl, 0.01 of which are used up in the neutralization, leaving 0.0087 moles of unreacted HCl.
being able to fully ionize, the H+ concentration is that of the entire molecule.

THEREFORE pH = -log(0.0087)
= 2.06 ????

no one seems to agree with me
i think that was the D option

if i'm wrong, please explain
 

Joy_2575

Member
Joined
Jun 30, 2011
Messages
126
Gender
Female
HSC
N/A
Re: CSSA Chemistry 2011

even though im over thinking this... i need a second opinion.
for the Ba(OH)2 and HCl question heres what i did

25mL of 0.75 mol/l HCl
10mL of 0.5 mol/l Ba(OH)2

when added
==> (0.75)(0.025)=(0.035)x ==> x= 0.5357 mol/l of HCl [new concentration] 0.0187 moles of HCl present in total
==> (0.5)(0.01)=(0.035)y ==> y= 0.142857 mol/l of Ba(OH)2 [new concentration] 0.005 moles of Ba(OH)2 present in total

2HCl + Ba(OH)2 ----> BaCl2 + 2H2O
2 : 1 1 : 2

for the neutralization to occur... the double the amount of Moles of Ba(OH)2 is needed for HCl.
2HCl + Ba(OH)2 ----> BaCl2 + 2H2O
0.01 0.005

in total there are 0.0187 moles of HCl, 0.01 of which are used up in the neutralization, leaving 0.0087 moles of unreacted HCl.
being able to fully ionize, the H+ concentration is that of the entire molecule.

THEREFORE pH = -log(0.0087)
= 2.06 ????

no one seems to agree with me
i think that was the D option

if i'm wrong, please explain
Could you please re state the question that was in the test?
 

Solie

New Member
Joined
Aug 5, 2011
Messages
1
Gender
Male
HSC
2011
Re: CSSA Chemistry 2011

leaving 0.0087 moles of unreacted HCl.
being able to fully ionize, the H+ concentration is that of the entire molecule.

THEREFORE pH = -log(0.0087)

You used number of moles, rather than concentration. What you should have done is: c=0.0087/0.0035 , then log it. (35 mL is the total amount of liquid used).
 

Joy_2575

Member
Joined
Jun 30, 2011
Messages
126
Gender
Female
HSC
N/A
Re: CSSA Chemistry 2011

leaving 0.0087 moles of unreacted HCl.
being able to fully ionize, the H+ concentration is that of the entire molecule.

THEREFORE pH = -log(0.0087)

You used number of moles, rather than concentration. What you should have done is: c=0.0087/0.0035 , then log it. (35 mL is the total amount of liquid used).
Hey Solie :)
would you remember the question?
 

Askanison

New Member
Joined
Jan 1, 2009
Messages
4
Gender
Male
HSC
2011
Re: CSSA Chemistry 2011

leaving 0.0087 moles of unreacted HCl.
being able to fully ionize, the H+ concentration is that of the entire molecule.

THEREFORE pH = -log(0.0087)

You used number of moles, rather than concentration. What you should have done is: c=0.0087/0.0035 , then log it. (35 mL is the total amount of liquid used).
FARK
i realised that 3 seconds after posting...
there goes another mark...

thanks either way... stupid mistakes such as these always keep me from full marks. currently sitting on 97... hopefully :)
 

Riproot

Addiction Psychiatrist
Joined
Nov 10, 2009
Messages
8,228
Location
I don’t see how that’s any of your business…
Gender
Male
HSC
2011
Uni Grad
2017
my english co-ordinator did the same thing. UR NOT GOOD ENOUGH TO DO ADVANCED UR NOT GOOD ENOUGH etc etc. but 44 percent of kids get band 5 im guaranteed band 4...while in standard 6 percent get band 5 and like 12-18 get band 4, and l unfortunatly moved down standard coming top 20 /136 ...dumb bitch
My teacher just told me I had a bad attitude and that he didn't like me. :/
 

Joy_2575

Member
Joined
Jun 30, 2011
Messages
126
Gender
Female
HSC
N/A
what was the prac that was in the CSSA paper? and also did you guys have a question on dry cells?
We had to explain how a titration was carried out..lol
 

muzeikchun852

Active Member
Joined
Mar 29, 2009
Messages
1,590
Gender
Undisclosed
HSC
2011
i dont think the trial was too difficult. im sure i made a few mistakes along the way. but overall fine. hoping i can pull off 85+.
 

Dylanamali

Active Member
Joined
Jul 7, 2009
Messages
1,248
Gender
Male
HSC
2011
what was the prac that was in the CSSA paper? and also did you guys have a question on dry cells?
We had to explain how a titration was carried out..lol
We had a question on dry cell/lead acid cell vs another cell in terms of chemistry and impact on society.
 

Riproot

Addiction Psychiatrist
Joined
Nov 10, 2009
Messages
8,228
Location
I don’t see how that’s any of your business…
Gender
Male
HSC
2011
Uni Grad
2017
How can you write 3 pages?? When the space for your answer is allocated ?


I myself filled the whole thing. I just talked about Haber process, him helping the german movement, and the knowledge of equilibrium enhancing ...
Yeah I did that too. Btw, my teacher advised me to use an extra booklet as he hates my writing and told me to space and write big. Although I kinda didn't.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 2)

Top