How was chem 33...:D And my Guesses:D..

[darkism]

had a superb paper....

 

[princesszahra]

mashallah

 

[mariam]

wow..!
mashALLAH..!

 

[mariam]

ny prediction for bio p4?? :mrgreen:

 

[Aamir Khan]

hey..cud u tell me the anions for each of fa2,3 and 4
and how many marks could i lose if i had a molar enthalpy change of 16 in my calculations..

 

[mista.lova.lova]

for chem p 33:-
Anions: Sulphate in all three, Carbonate in FA 3 n 4
Cations: copper, ammonium, manganese n again mangansese

cldnt cmplete the ppr coz of stupid superwiser, he said us to do Q2 first..
anyways A InshAllah pakka hai ppl..

 

[Aamir Khan]

umm..did u check the solutions for solubility of white ppt cuz by adding acid in fa3 my white ppt dissolved so technically there should be no sulphate?

 

[mista.lova.lova]

nah...i fogot.. :|
damn...chalo khair....my frnd got a U last yr in pract, bt overall he had A...so no tensions..

 

[darkism]

yea when i added acid ppt disapeard but as they were askin i dint pay atention to it n wrote wt i predicted....as there was no other option...

 

[zahraahmed]

http://notezone.net/cambridgechem/chemi ... sis%5D.pdf can sum1 go in dix page 11 n do solve n gimme answers plzzzz i cant able to slove it n it might cum for exam help mee!!!!

 

[thunderingthunder]

can anyone tell me did the guesses actually work???

 

[Feelguud77]

Chem 33 done?! I have it tomorrow!! Eager :F

 

[filza94]

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