## 2002 - Multiple Choice - Q12,Q14,Q19,Q27,Q29 help needed

### mujb

Posted 27 May 2006 - 02:39 PM

anyhelp appreciated

### Michael

Posted 27 May 2006 - 02:57 PM

I would but i bet pammy is already busy working away since she is already viewing the topic.

### Pammy

Posted 27 May 2006 - 03:06 PM

I dont know how to do 12

Question 14

Re-forming produces branched molecules, so if you draw out each of the products you should see that B is the only one with a branch

Question 19

you need to find a pattern which constantly repeats itself
which is the
CH3-CH-CH-CH3
aka. the first H shape

straighten it out, add your double bond and you should get But-2-ene

Question 27

In a redox reaction there must be a reduction and oxidation taking place.

Look at B
Zn --------> ZnCl so the Zn is now positive, and has lost an electron, it has been oxidised
2HCl -------> H so the H+ is now neutral, and has gained an elector, it has been reduced

Question 29

Strontium is atomic number 38
It tells us it has a mass number of 90
No. of neutrons = mass no. - atomic no. = 90-38 = 58
No. of protons = atomic no. = 38

ratio = 58:38
58/38 = 1.37

QUOTE(Dhesi @ May 27 2006, 02:57 PM)

I would but i bet pammy is already busy working away since she is already viewing the topic.

Haha lol yes I was, but could you do question 12 ??? Please !!!!!!

### Michael

Posted 27 May 2006 - 03:22 PM

Yeah no probs, it is quite a weird question.

12. Carbon 12 has 6 protons and 6 neutrons per atom therefore 12x3= 36 quarks
In 12g of carbon-------> 36x6x10^23
In 1g of carbon--------->(36 x6x10^23)/12 = 1.8x10^24

### Pammy

Posted 27 May 2006 - 03:29 PM

QUOTE(Dhesi @ May 27 2006, 03:22 PM)

Yeah no probs, it is quite a weird question.

12. Carbon 12 has 6 protons and 6 neutrons per atom therefore 12x3= 36 quarks
In 12g of carbon-------> 36x6x10^23
In 1g of carbon--------->(36 x6x10^23)/12 = 1.8x10^24

Thanks, I was being really daft, thought there were 12 protons Hahah and I'm supposed to be sitting Higher Chem on tues !!!

### Michael

Posted 27 May 2006 - 03:31 PM

After this exam I think i might make worked solutions to all the bloody papers because the lack of them online is really beginning to annoy me.

### Pammy

Posted 27 May 2006 - 03:34 PM

I wish there was a bit in the Chem forum for the problem questions like there is in maths because it makes it so much easier, especially the way it has all been summarised (by George I think)

edit: meant an index when i was talking about it being summarised there, couldn't remember the word hee hee !!

### Michael

Posted 27 May 2006 - 03:35 PM

If we got like 5 people to do one paper each I think the world would be a better place for future generations.

### Pammy

Posted 27 May 2006 - 03:37 PM

Well I would definately agree to do that after my exams are over with !!!
I'm assuming you would too Dhesi ???
That's two down, three to go !!

### Michael

Posted 27 May 2006 - 03:38 PM

Ive already done them all so ive got answers, its just the time to type them out. After tuesday I will be doing so.

### Pammy

Posted 27 May 2006 - 03:39 PM

Yay !!!!
wish someone last year had decided to do that tho !!

### Michael

Posted 27 May 2006 - 03:51 PM

Im bored atm so ive started 2005.