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chem A2

A

angel eyez

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IS AS IMPORTANT FOR P4??
WAT SHULD V STUDY OF AS FOR PPR 4...??
R V SUPPOSE TO GO IN DEPTH??
ANY RESPONSE WILL B APPRECIATED...
PLZ ANY1 HELP...
 
aquariangurl

aquariangurl

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Honey, High time you asked that question!
Go through your syllabus, whatever is in BOLD is your A2 syllabus -.-! & yes do not forget to go through the application booklet becauze section B is totally based on it.
Solve starting from the latest papers & then if tym allows keep moving backwards..post ur doubts on the forum & we all are here to help
 
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filza94

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http://notezone.net/cambridgechem/chemi ... sis%5D.pdf below answer go page 11

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
 
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blueindigo

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Yupp!!! if you look at the recent yrs, u'll find the organic is mostly of AS, sumtimes more than the a2 part, so yeah..organic AS is needed, as well as the enthalpy chapter of AS...thats all i guess!! and for the application part, there is some bio of AS to study..if you remember DNA structure
Hope that helps!! :)
 
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filza94

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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!!!!
 
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filza94

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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....:)
 
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