Paper 5 Tips !! :)

[Soldier313]

look dont over-complicate stuff.. do what makes sense.. ALWAYS use the same number of sig.figs or decimal places as the information in the question UNLESS stated otherwise

okay bruv, thanx for that advice!!

Oui... u gotta a point...

i knowwww sis!

 

[knowitall10]

I guess we try to 'minimise' not 'prevent' the heat loss by using a lid. The usage of lid can be tricky sometimes. For instance, in a situation where you have to add a solid to the acid contained within the cup, you cannot just add it all at once and cover the cup.

Yeah well obviously common sense does kick in sometimes.. but in general, we prevent heat loss cuz its totally impossible to stop it.. SubhanAllah...

 

[VelaneDeBeaute]

dude! chill!
look at that column, where the values are 2.600, 3.983......
that looks like 4 sgf to me not 2 dp!
View attachment 25406

When there is no specification, you go for the two decimal places thing. However, for tables as you've mentioned there are two things. One, if one entry in that specific column is already given to 4 significant figures, give all the answers to that degree. Second, if none of the answers are given, you can choose to go by the least count of the device. e.g. 2.20 g if you're using a mass balance that is accurate to 0.01 g.

 

[Soldier313]

When there is no specification, you go for the two decimal places thing. However, for tables as you've mentioned there are two things. One, if one entry in that specific column is already given to 4 significant figures, give all the answers to that degree. Second, if none of the answers are given, you can choose to go by the least count of the device. e.g. 2.20 g if you're using a mass balance that is accurate to 0.01 g.

Thank you! exactly what i needed!
God bless yu!!

 

[Jiyad Ahsan]

dude! chill!
look at that column, where the values are 2.600, 3.983......
that looks like 4 sgf to me not 2 dp!
View attachment 25406

okay listen... go back to the ms.. not the appendix the place where its written "correctly calculates the ratio....."
the place where it says "see appendix" look above it it says what ? "calculation MUST be to 2 decimal places"

 

[knowitall10]

okay listen... go back to the ms.. not the appendix the place where its written "correctly calculates the ratio....."
the place where it says "see appendix" look above it it says what ? "calculation MUST be to 2 decimal places"

Sorry to put u into this bro..lol...
but you're good.. keep it up

 

[Jiyad Ahsan]

Sorry to put u into this bro..lol...
but you're good.. keep it up

dont give up do I ? i know i'm annoying

 

[Student12]

for d part:
it means higher mass are not seen to give expected results, either they are lower means more CuO is supposed to be more than it is means some CuO is blown out
if higher incomplete decomposition!
for f
pick any point of your x-axis draw a line from that point to the line of best fit and then see its Y-axis thenapply unitry method to find its formula

Whats the unitry method ?

 

[xhizors]

Hey how wud i find the solubility of cerium sulfate in sulfuric acid? 5 mold dm-3 sulfuric acid, by the way

lots of prayers in advance

calculate the mr of sulfuric acid and find out its mass per dm3
98x5= 490g
assumption of 1 g = 1cm3
means 490g = 490cm3
solubility = (mass of cerium guy x 100) /mass of sulfuric acid
u multiply it by 100 only if ur finding solubility in 100g
hope that helps

 

[xhizors]

stuck sumwhr?? or lets say its tym to panic!! im freakin out..forgttin everythng tat i stdy!!

lol!! common man what to freak out u r payying to give paper not they are suing you !!

 

[knowitall10]

dont give up do I ? i know i'm annoying

Naah... you're not annoying... Keep up the spirit!! It's annoying when people give up.. it's cool when you dont

 

[knowitall10]

lol!! common man what to freak out u r payying to give paper not they are suing you !!

Perform you Salah at it's respected times (not only when exams come up ) and you'll be good! And ask you parents' for Duaas..thats the best key to succeed

 

[knowitall10]

GOOD LUCK FOR THE PAPER 5 BROTHERS AND SISTERS!!!!
INSHALLAH, WE'LL ACE IT
AND xhizors WILL GET THE WORLD DISTINCTION!!!! INSHALLAH!!!!

 

[xhizors]

the marking scheme says:

Showing a condenser and collector for water (e.g. cooled (ice)
U-tube) connected to the ammonium nitrate apparatus. If a gas
collector is after this piece then the water collector must be gas
tight. If no gas collection is attempted after the water condenser
then it must be open to air. Allow a Liebig condenser provided it
fulfils the same conditions as stated above.
can somebody elaborate what is required in the highlighted and underlined phrase

i think they meant their mustn't be any gas in a collector, its not confirm some one show light plz

 

[xhizors]

Perform you Salah at it's respected times (not only when exams come up ) and you'll be good! And ask you parents' for Duaas..thats the best key to succeed

thats the best and only way to get the unlimited success,, BRING IT ON

 

[Jiyad Ahsan]

Whats the unitry method ?

oh its like since the gradient of line is constant, umm if from your construction line you find that with one unit of x you have 2 units of y... so umm 2 units of x would give you 4 units of y.
( umm another way of saying it is like 'A man walks seven miles in two hours. What is his average speed? so since his speed is constant, you half the x (time), and half the y(distance).. you have 3.5 miles/hour !)

sorry if i confused you..

 

[zsyed94]

I didnt look at the mark scheme yet for q1 c but this is my diagram:
For the next question:
the two stated volumes of the water layer and ether layer can be taken as the volume of succininc acid.
so to find it's conc in the water layer (column D), we have to realize that 1mol of NaOH=2mol of succinic acid. because NaOH has one OH gp whereas succinic acid has two OH gps.
So.. B x 0.1= 2( D x 10)
therefore, 0.1/20 B= D
You apply the same method for the conc of succinic acid in ether.
Got it?
I'll check the marking scheme for my diagram...

Can you please tell how you calculated the concentration of the acid after calculating the moles of succinic acid?

 

[xhizors]

problem here

check out june 2012/52/q2 part(b)

A graph is to be plotted. the question says draw a line of best fit and the marking scheme says
checkfor a slightly downward sloping continuous curve.No straight/horisontal line.
Does it mean that we have to draw a smooth free-hand curve

Line of best is not the straight line, its the line with the most points on it
did that help?

 

[knowitall10]

i think they meant their mustn't be any gas in a collector, its not confirm some one show light plz

i think they meant their mustn't be any gas in a collector, its not confirm some one show light plz

I hope this helps brother..

 

[xhizors]

in october 2010
how do u find the conc in oth the solution...
and the K value can it be either way
water over ethyl and ethyl over water

post link for fast response plz