Author Topic: Tough chem p6 questions from 1990-1995-help plz!!  (Read 1447 times)

Offline angell

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Tough chem p6 questions from 1990-1995-help plz!!
« on: May 13, 2009, 07:13:39 pm »
Going through past papers from 1990 to 1995, I found these questions that i got a lil confused in. Appreciate it if someone could answer them plz?


1. A student heated some ethanol in a test tube. Write down two expected observations.


2. A general purpose cleaner is made up as follows:

Soluble substances                       % by mass
fomaing agent                                10
ammonia                                         5
bleaching agent          12
binding agent         10
detergent         19

Insolube substances               %by mass
Calcium carbonate                 44

Outline, with experimental details, how you would show that the cleaner contains 44% of insoluble material.

3. A farmer needs to test and compare the acidity of two samples of soil from different fields. Outline how the farmer should carry out these tests.

4. You are provided with samples of three metals: copper , zinc and magnesium. Outline an experiment that could be carried out to show their order of reactivity. Marks will be awarded for practical details and observations.

5. Four unlabelled bottles of chemicals each contained one of the following liquids:

Aqueous copper(II)sulphate
Pure water
Hexane(an alkene)
Limewater
State observations or tests by which you could correctly label each bottle.
oh churiyaan charha dey..
oh mehndiya kara dey..
oh jhanjara pawan dey...
On the dance floor oh mundiye...Nach Baliye!

--~*O yaara dhol bajaake.. O yaara jashan mana ke!!




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Offline angell

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #1 on: May 13, 2009, 08:04:18 pm »
Anybody??? :(
oh churiyaan charha dey..
oh mehndiya kara dey..
oh jhanjara pawan dey...
On the dance floor oh mundiye...Nach Baliye!

--~*O yaara dhol bajaake.. O yaara jashan mana ke!!




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Offline Naruto

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #2 on: May 13, 2009, 09:08:14 pm »
hey i have the answers from 1993 to 2008 on ward so can you tell me the year??????????

Offline astarmathsandphysics

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #3 on: May 13, 2009, 09:34:47 pm »
Can you send them to me?

Offline angell

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #4 on: May 13, 2009, 09:36:39 pm »
hey naruto....could u plz check cuz i have no idea now!! some of it is from 1991 too:(:(
oh churiyaan charha dey..
oh mehndiya kara dey..
oh jhanjara pawan dey...
On the dance floor oh mundiye...Nach Baliye!

--~*O yaara dhol bajaake.. O yaara jashan mana ke!!




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Offline anshasi

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #5 on: May 13, 2009, 10:08:53 pm »
q1)a)ethanol will catch fire(light up with fire).
b) i only know 1 .

q2)A)we take a sample of the cleaner in a test tube
B) we put the test tube in water bath till all liquid is evaporaed and only solid is left.
C)we take the solid left and we add water on it. the solid should not dissolve if it is insoluble.

q3)we take soil samples from both feilds ,we put them in test tube A, and test tube B.
we crush both soil samples(each by its own) using pestal and mortar. then we add water on crushed soil samples and we stirr using a glass rod.then we make filtration to the mixture(u may draw it) , and we take the solute.
using a pH meter we measure the pH of both samples.

q4)we do the following rxn(i did not specify cause i am tired!)
rule for u: there is no rxn between less reactive metal(ex:Zn) and more reactive metal ion(MgO).
1)Cu + ZnO= no rxn
2)Zn+MgO= no rxn
3)Cu+MgO=no rxn


q5)we take three samples from each chemical from the bottles.
from the first sample of each bottle we add drops of NaOH, the sample which is copper(II) sulphate forms a pale blue percipitate.

from the second sample of each bottle , we put each sample(seperated) in a watch dish and we touch its surface with a lighted splint the sample which is alkene will catch fire.

from the third sample of each bottle, we put in a beaker and we put a delivery tube in it(under the liquid) and we respire(blow) through the tube , the sample which is limewater will turn milky.

ah finally finished :o ;)

Offline anshasi

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #6 on: May 13, 2009, 10:33:54 pm »
actually the 4th question is the hardest one!
i don't think any of these will come.  8)

Offline Muho

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #7 on: May 14, 2009, 12:09:18 am »
I agree. If I were you I would've concentrated on the recent ones, Eg. 2003 onwards. If you did that already that's more than enough o.O 1995. God knows how many times the syllabus changed by then.
Shim.

Offline angell

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Re: Tough chem p6 questions from 1990-1995-help plz!!
« Reply #8 on: May 14, 2009, 01:36:40 am »
THANKS LOADZZ anshasi....:)

yeahh ive already done the 2000z...so wanted to tackle the old ones too...:)
oh churiyaan charha dey..
oh mehndiya kara dey..
oh jhanjara pawan dey...
On the dance floor oh mundiye...Nach Baliye!

--~*O yaara dhol bajaake.. O yaara jashan mana ke!!




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