Chemistry Paper 3 Practical Dilution tutorial and notes... :

[AngelofDeath]

First, use the equipment you are told to use to take in the amount of liquid you need. (Example: Measure 45.00 cm3 of FA1 using a measuring cylinder into the volumetric flask labeled FA3).
Second, wash or rinse the beaker using DISTILLED WATER and pour ALL the washings or rinsing inside the volumetric flask labeled FA3. This ensures that all the FA1 is inside the volumetric flask.
Third, use the distilled water bottle to fill the volumetric flask till the 250 cm3 mark (most commonly an etch on the neck of the flask). To do this quickly yet precisely: remove the cap of the water bottle and pour distilled water until you reach the beginning of the neck. Then screw the cap back on and slowly squeeze the bottle ensuring you make the water stream flow on the neck of the flask to ensure no splashing occurs and that the flask fills in a gentle way (not like the Indian ocean amidst monsoon season).
Fourth, screw the volumetric flask's lid back on, and MAKE TRIPLE SURE IT'S CLOSED or else you'll have acid all over you and ******* up your exam and coming to this post and crying that I made you fail.. Then slowly invert the flask a number of times and between each invert swirl or shake the flask while holding it firmly (That's 320 grams of load your holding their so don't under estimate it ).
Fifth, voila there you go you've just completed your dilution both quickly and most importantly accurately.
Any questions feel free to post here and I will try to answer as quickly as possible as I have to study (DUH)..




GOOD LUCK EVERYONE <3 <3 <3 <3

 

[zahraahmed]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

ohhh sorrieee i did it bymistake......................

 

[AngelofDeath]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

ohhh sorrieee i did it bymistake......................

HAHAHA lol me too right now doing it by mistake..

 

[filza94]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

http://notezone.net/cambridgechem/chemi ... sis%5D.pdf plz go dix link pg 11 n c answers below of it

First of all you need the mass of FA1. In the first table you have the mass of the empty test tube and the

mass of the test tube + FA1. All you do is subtract the values 12.80 - 10.50 giving you 2.30g of FA1.

In the second table you need the mass of FA1 after heating. Again, you just subtract the values 11.76 -

10.50 = 1.26g FA1 after heating.

1 d. (i) The mass of anhydrous XS04 present in the crystals is what is left over after heating = 1.26g

1 d. (ii) The mass of water driven from the crystals is the loss in mass that has occurred when the FA1 was

heated. Before heating there were 2.30g of FA1 and after heating there were 1.26g. So the mass of water

lost is 2.30 - 1.26 = 1.04g

1 e. To calculate the number of moles of water in the sample of FA1 you use the formula no. of moles =

mass/mass of 1 mole which gives you 1.04/18 = 0.058 mol

1 f. The number of moles in XSO4
7 moles of H20 gives 1 mole XSO4 (from the formula XSO4.7H20)
So 0.058 moles of water give 0.058/7 = 8.29 x 10 ^ -3 moles of XSO4

1 g. To calculate the relative formula mass of XSO4 you use the formula mass of 1 mole = mass/no. of

moles which gives you 1.26/8.29 x 10 ^ -3 = 152.7

1 h. To calculate the Ar of element X you first find the Mr of SO4 which is 32 + (4 x 16) = 96
You subtract this from the RFM from part g giving you 152.7 - 96 = 56.7

 

[honeyDew]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

@angelofdeath
ab yeh kaisa experiment hai....is it given in any of the pastpapers?

 

[filza94]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

jux go on dix plzzz n ask for details viewtopic.php?f=26&t=1370 fast fast these ppl hav given there exam paper 33 chemistry n get details

 

[AngelofDeath]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

No no ppl.. this is not what's included in the test.. These are just notes on how to properly do the dilution for te titration as I knew that alot of ppl are having immense troubles with it..

 

[Hateexams93]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

i'm screwed

 

[filza94]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

by masterboss365 » Wed May 11, 2011 5:08 pm
Tritration with KMnO4, sodium thiosulfate, potassium iodide
J07/32, J08/31, N08/32,

Heating related question. Find water of crystallisation. Heating (may be CuSO4 hydrated ) and then finding mass of water lost. Check for percentage of water present. J08/32, J09/32,

Salt anylsis
NH4+, Br-, NO3-, CO32-,
ammonium sulfate, zinc nitrate, ammonium bromide


Thanks,
Not sure 100%.

 

[zahraahmed]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

I need help asap for question 2(e) in June 07 Chem p5, I have already drawn the graph however I just dont know how to find 'x' ...

http://www.xtremepapers.me/CIE/Internat ... 7_qp_5.pdf

 

[filza94]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

hmm letme try to find out frm ym frnds!!!!

 

[filza94]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

Topic To Stress On Biology Paper 22 AS
Gaseous exchange
Infectious diseases
Immunity
Transport: In plants- all the pathways in the cell (apoplast n symplast)
in humans- cardiac cycle, pressure graph, etc...
Nitrogen cycle

Itx surely cuming as my Biology Teacher predicted them every year she does n it cumss last year 4 my O level also she predict so i got A* n dat all camee now she precdicted for AS Paper 33 so evryone study all topics anyway so focusing on these shouldn't make u forget the others!!!!

 

[zahraahmed]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

guys shes wrong
just check my post!!
viewtopic.php?f=26&t=6663

 

[filza94]

Re: Chemistry Paper 3 Practical Dilution tutorial and notes.

m here to help u all trust mee m a inocent girl want evry1 to get a goof grade m not lieing my teacher also told me dat all bt i saw sumesle posting it so i also post it seriously abt chemistry info i was rite as my teacher i especially called her n asked she told me as she was making solutions n saltss....

 

[Velammal]

Can anyone help me to do the dilution related question in 9701_y16_sp_3 Question no: 2. a). ??????? Actually I dont understand what they mean by run between 9 and 12 cm3.