MedVision ad

Thoughts on CSSA chemistry? (1 Viewer)

LMoura

New Member
Joined
Dec 24, 2012
Messages
10
Gender
Male
HSC
2013
I heard the industrial chem questions threw a bit of people off? What are your thoughts on that? And also what did most people write for that Davy question?
 

ocatal

Active Member
Joined
Sep 1, 2012
Messages
298
Gender
Male
HSC
2013
I heard the industrial chem questions threw a bit of people off? What are your thoughts on that? And also what did most people write for that Davy question?
I spent way too much time on the two 6 mark questions for Industrial and ended up having to guess a few multiple choice questions because of it.
 

Siddy123

Active Member
Joined
Sep 30, 2011
Messages
672
Location
Compton
Gender
Male
HSC
2013
what did u guys get for the mass of the the other thing? ( cant remember the question exactly but 2 of the others were 500g and they gave us the mm of each one)
 

LMoura

New Member
Joined
Dec 24, 2012
Messages
10
Gender
Male
HSC
2013
what were the two questions again? Sorry i forgot them. And mc was decent however time was tight due to the extended response/ short answer questions.
 

LMoura

New Member
Joined
Dec 24, 2012
Messages
10
Gender
Male
HSC
2013
I spent way too much time on the two 6 mark questions for Industrial and ended up having to guess a few multiple choice questions because of it.
what were the two questions again? Sorry i forgot them. And mc was decent however time was tight due to the extended response/ short answer questions.
 

Streetboy

Member
Joined
Jan 12, 2013
Messages
186
Gender
Female
HSC
N/A
how did every find the question on the account the ph, something like 0.5?

Did you have to minus the two numbers to get 0.5, say why. ( I think it was 3 marks).
 

BabzBrah

Member
Joined
May 12, 2012
Messages
38
Gender
Male
HSC
N/A
How'd use all go on the long response questions, I think I went ok.
 

mac1996

Member
Joined
Oct 16, 2012
Messages
354
Location
Sydney
Gender
Male
HSC
2013
how did every find the question on the account the ph, something like 0.5?

Did you have to minus the two numbers to get 0.5, say why. ( I think it was 3 marks).
oh i just said, its because of the large difference in volumes of the water and acid (was talking shit)
then i said it was also coz ethanoic acid is a weak acid, so on so.
 

Siddy123

Active Member
Joined
Sep 30, 2011
Messages
672
Location
Compton
Gender
Male
HSC
2013
how did every find the question on the account the ph, something like 0.5?

Did you have to minus the two numbers to get 0.5, say why. ( I think it was 3 marks).
i wroe that she based it on the original volume (100mls) so when u added the 10ml it became 110ml and then u do it for that.
then did c1v1 before= c1v1 after and found the new conc
and took -log turned out to be whatevs she wanted so yeh
 

Siddy123

Active Member
Joined
Sep 30, 2011
Messages
672
Location
Compton
Gender
Male
HSC
2013
What was the pH question? Interested.
a bitch found the pH of a 100ml solution
she added 10ml of water
she expected that her pH would drop by 1 unit but it dropped by 0.5
explain why etc etc

something like that^^^
 

mac1996

Member
Joined
Oct 16, 2012
Messages
354
Location
Sydney
Gender
Male
HSC
2013
i wroe that she based it on the original volume (100mls) so when u added the 10ml it became 110ml and then u do it for that.
then did c1v1 before= c1v1 after and found the new conc
and took -log turned out to be whatevs she wanted so yeh
bro i think ur right
i never thought of that in the exam
i just hope i dont move down too many ranks :s
 

sabrelord3

New Member
Joined
Jul 16, 2012
Messages
5
Gender
Male
HSC
2013
What were the industrial questions about? I heard they were pretty hard
 

JBee

Member
Joined
Jul 29, 2013
Messages
39
Gender
Female
HSC
2013
i wroe that she based it on the original volume (100mls) so when u added the 10ml it became 110ml and then u do it for that.
then did c1v1 before= c1v1 after and found the new conc
and took -log turned out to be whatevs she wanted so yeh
The pH change was less than she thought because when we calculate pH with -log[H+] we're assuming that the acid fully ionises... but as you know ethanoic acid is weak (doesn't fully ionise in sol'n) so she'd need to calculate the degree of ionisation before she could calculate the pH
 

pscecelia

Member
Joined
Dec 16, 2011
Messages
150
Gender
Female
HSC
2013
multiple choice was soooooo tough! forensics amino acids..woooppss didn't study that. the short response was pretty good :D

what marks are you guys aiming for? I'm hoping a 70% plsssssssss
 

mac1996

Member
Joined
Oct 16, 2012
Messages
354
Location
Sydney
Gender
Male
HSC
2013
multiple choice was soooooo tough! forensics amino acids..woooppss didn't study that. the short response was pretty good :D

what marks are you guys aiming for? I'm hoping a 70% plsssssssss
yeah ill be happy with 70
but im not confident with my answers, so i might end up getting really shit
 

Siddy123

Active Member
Joined
Sep 30, 2011
Messages
672
Location
Compton
Gender
Male
HSC
2013
The pH change was less than she thought because when we calculate pH with -log[H+] we're assuming that the acid fully ionises... but as you know ethanoic acid is weak (doesn't fully ionise in sol'n) so she'd need to calculate the degree of ionisation before she could calculate the pH
shit. ur right.
i forgot to calculate it and prove it ( though i mentioned it in my first line i think). :(
 

JBee

Member
Joined
Jul 29, 2013
Messages
39
Gender
Female
HSC
2013
multiple choice was soooooo tough! forensics amino acids..woooppss didn't study that. the short response was pretty good :D

what marks are you guys aiming for? I'm hoping a 70% plsssssssss
I'll be happy with 80%, but I'd rather 88+ because that's what i got in half yearlies :/
 

bfoo

New Member
Joined
Jun 20, 2012
Messages
17
Gender
Male
HSC
2013
The pH change was less than she thought because when we calculate pH with -log[H+] we're assuming that the acid fully ionises... but as you know ethanoic acid is weak (doesn't fully ionise in sol'n) so she'd need to calculate the degree of ionisation before she could calculate the pH
yer this is what i wrote
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top