Chemistry Unit 3 exam discussion here >>>>

[shoaeb]

i d

i not have the physics practical book !!!!
>.<
i dont even know from where to study... from where did u get the book ????
if its possible... cud u send a link to a pdf of it ???

im not talking about the practical book..the general physics AS book..the one with unit 1 and 2 in them..go through unit 1 and 2..youll find a couple of experiments..check them out..also check the link posted by yousef in this thread..

 

[RedRose91]

im not talking about the practical book..the general physics AS book..the one with unit 1 and 2 in them..go through unit 1 and 2..youll find a couple of experiments..check them out..also check the link posted by yousef in this thread..

hahaa lol alright !!
stupid me :$
thanks still !! XD

 

[shoaeb]

hahaa lol alright !!
stupid me :$
thanks still !! XD

no worries ..goodluck

 

[AhmadArabiyat]

Hope all of you did well, the exam was pretty weird today, a very different form from all the past papers. For the Hess' law question, i got the answer +94, 2 moles of KHCO3 react, so delta H1 multiplied by 2 As for the percentage error, i got a pretty weird thing, 0.047%, this is what i've done: 2*0.005*100/21.49, did anyone do such thing? Improvements: cover with a lid (stupid answer in my opinion) use oven to dehydrate the crystals instead of heating in a crucible Anyone have any idea about the effect of errors on x and water?

 

[simim]

delta H1 was +30 kj/mol
delta H2 was - 34 kj/ mol
delta Hr was = delta H1 - delta H2
= 30 - (-34) = 64 kj/mol

R u sure about dis answer cz some ppl were lyk u have 2 multiply it by 2 cz it was mentioned in the equation

 

[simim]

No H1 was 2(30) so Hr = 2(30)-(-34) = 94kj/mol

R u sure it has 2 b multiplied by 2?

 

[Stoner]

R u sure it has 2 b multiplied by 2?

yah m sure it has to.. even other past paper Q have d same concept.

 

[yousef0074]

But this is unfair as it's from unit 1, and didn't get to revise it. Expected questions on energetics were the usual ones that come repeatedly in unit 3 past papers

 

[AhmadArabiyat]

But this is unfair as it's from unit 1, and didn't get to revise it. Expected questions on energetics were the usual ones that come repeatedly in unit 3 past papers

Actually, check the revision guide, pages 114-117 describe what might be included in the practical investigation exam, one of them is Hess' Law

 

[shoaeb]

Actually, check the revision guide, pages 114-117 describe what might be included in the practical investigation exam, one of them is Hess' Law

yeah but they werent there in the past papers..totally unfair..not even a single graph

 

[Shuvo Mehedi]

Can anyone please post all the answers of question no. 4 and 5???........please kindly post if u know

 

[shoaeb]

Can anyone please post all the answers of question no. 4 and 5???........please kindly post if u know

can you remind us what question 4 and 5 are -_-

 

[z3r0thunder]

it was 64 kj/mol

I found this value

ΔHr = 2ΔH1 - 2ΔH2
ΔHr = +2(30.0) - 2(-34.0)
= 128 kJ/mol

 

[U stalking ME]

lets stop arguing now on whose answer is correct and concentrate on other subjects, there is no point of crying over spilled milk

 

[¦HaLo¦]

lets stop arguing now on whose answer is correct and concentrate on other subjects, there is no point of crying over spilled milk

ikr