Multiple Choice (4 Viewers)

jamesfirst

Active Member
Joined
Jan 30, 2010
Messages
2,005
Gender
Male
HSC
2011
1. a
2. d
3. c
4. d
5. b
6. a
7. b
8. c
9. a
10. a (woops......)
11. d
12. c
13. c
14. d
15. b
16. b
17. c
18. a
19. b
20. d


.... who else got the same ?
 
Last edited:

jung1239

Member
Joined
Mar 15, 2011
Messages
113
Gender
Male
HSC
2011
So many different answers. Cant tell which ones are right.
 

Wentworth

Member
Joined
Oct 21, 2011
Messages
81
Gender
Male
HSC
2011
15 was A, all weak acids/bases are fully ionized in reaction with a strong acid/base ,and they're both monoprotic... that's my reasoning anyway anyone do the same?
 
K

khorne

Guest
1. a
2. d
3. c
4. d
5. b
6. a
7. b
8. c
9. a
10. a
11. d
12. c
13. c
14. d
15. b
16. b
17. c
18. a
19. b
20. d


.... who else got the same ?
1. a
2. d
3. c
4. d
5. b
6. a
7. b
8. c
9. a
10. c (as H+ reacts with CO3, Ba reacts with SO4 and then only CL is left)
11. d
12. D most negative voltage to most possitive
13. c
14. c 1,1 chloro bromo=3,3 chloro bromo, 1,2 chloro bromo, 1,2 bromo chloro, 2,2 bromo chloro, 1,3 bromochloro = 3,1 bromochloro
15. A or C is possible, but I think it is A, simply because if it didn't dissociate fully, we couldn't work out the concentration.
16. b
17. D 108/2800 = number of moles
18. a
19. b ( i think I put this down, I didn't mark an answer on my sheet)
20. b 200g of each you get 466.66+733.33, goes nicely.
 

silence--

Member
Joined
Apr 16, 2009
Messages
246
Gender
Male
HSC
2011
question 12 was D (DECREASING order - most reactive one first. the ones with negative reduction potential are stronger - see data sheet)

15 is A (i dont think it has anything to do with strength, its all V=n/c, 2010 hsc q7 had a similar question)
 

Hayzazz

Pig Member
Joined
Sep 2, 2009
Messages
345
Location
Sydney
Gender
Male
HSC
2011
Damn, I fucked up 12, I put C... Oh well, hopefully 19/20
 
Last edited:

jamesfirst

Active Member
Joined
Jan 30, 2010
Messages
2,005
Gender
Male
HSC
2011
1. a
2. d
3. c
4. d
5. b
6. a
7. b
8. c
9. a
10. c (as H+ reacts with CO3, Ba reacts with SO4 and then only CL is left)
11. d
12. D most negative voltage to most possitive
13. c
14. c 1,1 chloro bromo=3,3 chloro bromo, 1,2 chloro bromo, 1,2 bromo chloro, 2,2 bromo chloro, 1,3 bromochloro = 3,1 bromochloro
15. A or C is possible, but I think it is A, simply because if it didn't dissociate fully, we couldn't work out the concentration.
16. b
17. D 108/2800 = number of moles
18. a
19. b ( i think I put this down, I didn't mark an answer on my sheet)
20. b 200g of each you get 466.66+733.33, goes nicely.
14. 15.

are u sure?/
 

lolcakes52

Member
Joined
Oct 31, 2011
Messages
286
Gender
Undisclosed
HSC
2012
1/a 2/d 3/c 4/d 5/b 6/a 7/b 8/c 9/a 10/c 11/d 12/c 13/c 14/c 15/a 16/b 17/d(i think from memory) 18/a 19/b 20/b
15 is a due to the fact that the volume of NaOH is determined by the number of moles of acid which it reacts with, the number of moles of acid is determined by how many protons it can donate which in both cases is one. Therefore the amount of base required is the same.
 
Last edited:

timting95

Member
Joined
Sep 18, 2010
Messages
45
Gender
Male
HSC
2011
I'm just curious, for question 12 it says 'electrochemical activity' does that mean that it's from positive to negative, negative to positive, or actually the largest MAGNITUDE to the lowest... i.e. B
 

jamesfirst

Active Member
Joined
Jan 30, 2010
Messages
2,005
Gender
Male
HSC
2011
Shouldn't 14 be D and 15 be B ????


I even drew all the isomers and got 6 isomers.
 
K

khorne

Guest
14. 15.

are u sure?/
Yes, check it. I posted working

I'm just curious, for question 12 it says 'electrochemical activity' does that mean that it's from positive to negative, negative to positive, or actually the largest MAGNITUDE to the lowest... i.e. B
It doesn't matter. Electrochemical activity is the ability to engage in redox. The lower down, the less spontaneous
 
K

khorne

Guest
Shouldn't 14 be D and 15 be B ????


I even drew all the isomers and got 6 isomers.
Dude...m8...cool your jets

You have the following:

Cl and Br on the same C at the end and at the start is the same, so thats one. Then on the middle, that makes total of 2. You have Cl on end, br on other end which is another 1 (doesn't matter which side) so thats 3. Then you have Br in middle, cl on one end and Br on one end, cl in middle, that makes 2 more, so 5. It's 5. The rest are repetitions.

15 is not B because weak acids ionise fully in titrations with strong ones.
 

Nympha

Member
Joined
Jan 13, 2010
Messages
74
Location
Sydney
Gender
Female
HSC
2011
No, there's 5. I'm not sure about 15, I put B as well. Could someone explain this?
The answer would be A or C. A assumes degree of ionisation is irrelevant and that the weak acid will fully ionise. C assumes that a weak acid may not fully ionise, hence less H+ and hence less base is required to neutralize the H+.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 4)

Top