The 2004 HSC - Chemistry Paper (1 Viewer)

kow_dude

Active Member
Joined
Mar 9, 2003
Messages
1,270
Gender
Male
HSC
2004
very surprising... they didnt even mention the haber process as they did for the past few years.
 

dafidav

Member
Joined
Jul 6, 2004
Messages
430
Gender
Male
HSC
2004
can i ask what people wrote as their pH for that question where 0.01 mol/L HCl was diluted with 90ml water

i know the answer is either 3 or 5

what did people write??

i said 5
 

ay_caramba

Crazily Sane.
Joined
Apr 6, 2004
Messages
298
Gender
Female
HSC
2004
dafidav said:
can i ask what people wrote as their pH for that question where 0.01 mol/L HCl was diluted with 90ml water

i know the answer is either 3 or 5

what did people write??

i said 5
hehe i wrote pH 3
dunno if its rite
 

withoutaface

Premium Member
Joined
Jul 14, 2004
Messages
15,098
Gender
Male
HSC
2004
dafidav said:
can i ask what people wrote as their pH for that question where 0.01 mol/L HCl was diluted with 90ml water

i know the answer is either 3 or 5

what did people write??

i said 5
It was 3.
 

Leasha23

Member
Joined
Oct 20, 2003
Messages
35
dafidav said:
can i ask what people wrote as their pH for that question where 0.01 mol/L HCl was diluted with 90ml water

i know the answer is either 3 or 5

what did people write??

i said 5
yep it was three as far as i could work out!

pretty alright paper... some tough ones, but not too many calculations - something i was happy about!
 

froglenn

New Member
Joined
Mar 21, 2004
Messages
22
Gender
Undisclosed
HSC
N/A
dafidav said:
can i ask what people wrote as their pH for that question where 0.01 mol/L HCl was diluted with 90ml water

i know the answer is either 3 or 5

what did people write??

i said 5
i got 3, 0.01 x 0.01 = (concentration of hydrochloric acid) x 0.1

As hydrochloric acid is monoprotic, then hydrogen ion concentration is the same as hydrochloric acid, unlike say sulfuric acid. u get 0.001, which ends up as pH = 3, but i might be wrong (as i usually am :p).
 

jumb

mr jumb
Joined
Jun 24, 2004
Messages
6,184
Gender
Male
HSC
2004
I felt good when I read the paper, because when we were waiting to go in i go "quick, someone tell me an industrial isotope and what its used for!" So everyone got that question right :)
 

dafidav

Member
Joined
Jul 6, 2004
Messages
430
Gender
Male
HSC
2004
for that hcl qs

this is how i did it and got ph of 5

n=0.01 x 0.01
=0.0001

and then it was diluted to 100ml, so dilute factor of 10

so u divide 0.0001 by 10 and get 0.00001

so ph=-log[H+]

so =-log 0.00001

=5

but so many people sayings its 3
 

dafidav

Member
Joined
Jul 6, 2004
Messages
430
Gender
Male
HSC
2004
for that idustrial isotope

can u use technetium 99m??

cos like thats the medical industry

i wasnt sure if you could use medical industry
 

v-tech

New Member
Joined
Jul 29, 2004
Messages
9
That exam was so easy compared to the others like the trials. I reckon i got band 5 atleast
 

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

Top