IG Chemistry Paper 3 discussion

[a7medokool]

Hey guys for the empircal formula Question
u dividde the percentage by the RMM right i got 1.5 for mg i dont remember for the other element but if u get 1.5 is it times both by 2?

[sweetie]

oh
i got Mg₃N₂
by da way, which was in excess?
and wa was the no. of moles???

[IGCSE nightmare]

What makes you so sure ?!?
By the way I wrote that too but many are saying it's T3PO4

[qwert101]

I am so curious to find out the answers so pls answer my following questions:

1 What was the formulae of the metal T?n how to do that

2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)

3 What was the test to show that both lactic acid and acrylic acid contained the COOH group

I hope i'll get the answers soon
Thanx.

1. T3(PO4)2
2. i wrote Alkyl n alcohol
3. litmus ppr. turns BLUE litmus RED

litmus is an indicator

[zara]

Fluorine was in excess and silicon was the limitin reagent....
0.08 was the no of moles....cz the product is the same as dat of the limitin agent...dats wat i read in the txt bk...

[Kim]

What makes you so sure ?!?
By the way I wrote that too but many are saying it's T3PO4

believe me none of us are sure of our answers and dont worry I m sure we all will get marks that question was like wat 3 martks?so i m sure they will giv us 2 for nearly gettin our answers!!!!!!!!!!!!!!!!!!!!!!!!hehehe

[sweetie]

wa did u rite 4 da properties of Cao
i rote 1) it is basic
        2)it is soluble in water
and 4 the excess que. i got flourine
do u think mi answers r rite???

[xTremep]

1-WASHING THE PRECIPtate to remove impurities and get pure salt
2-heating in an oven to evaporate water and drying the salt
3-t3po4, because 18.0cm3 of T completely reacted with 6.0cm3 of po4 (from graph) there fore 18 is three times 6 .................
4-last page
i-the emperical formulae was Mg3N2
ii-silicon was limiting reagent
iii-0.08 moles

This is what i wrote exactly hope its correct

[sweetie]

was da qus bout the one in excess or da limiting reagent???

[mr3bood]

"Fluorine was in excess and silicon was the limitin reagent....
0.08 was the no of moles....cz the product is the same as dat of the limitin agent...dats wat i read in the txt bk..."

Yup!..i wrote silicon was the limiting reagent...........and for the very last question...i wrote 0.09 moles...!....hope its right...

I totally screwed up my exam!!....i think i'm going down to a C/D now...

[Kim]

1-WASHING THE PRECIPtate to remove impurities and get pure salt
2-heating in an oven to evaporate water and drying the salt
3-t3po4, because 18.0cm3 of T completely reacted with 6.0cm3 of po4 (from graph) there fore 18 is three times 6 .................
4-last page
i-the emperical formulae was Mg3N2
ii-silicon was limiting reagent
iii-0.08 moles

This is what i wrote exactly hope its correct

my moles was soo wrong
i got 0.095
cause i divided the value of f2 by 2
anyways themg2n3 taht is wrong cause u see after u get that u have to divide the values by the smallest which means 3/2=1.5=2 and 2/2=1 so the formuls mg2n(2 because u take the whole number)

[zara]

the ques was about the limiting reagent....
n 0.09 moles is nt rite....its 0.08 moles...
i messed up in the T metal thing...maybe also abt chloropyll....i rote the answer but not sure abt it....

[sweetie]

oops, i  only rote dat flourine was in excess   any problem???

wa did u ppl rite in da 2 blanks??
i rote carboxyl & hydroxyl
do u think it s rite?  

[zara]

the two blanks abt the acrylic acid??
well the answer was lactic acid and water

[Kim]

i messed up in the moles the last part only luckily but u never know how much more i have messed up
and in the blanks i wrote acid and alcohol group