Chemistry paper 31 (NEW)

[burndtjamb]

guys i found this post in studentsforum.biz
Many people have been asking about the new grade policy. In fact this is the most frequent qst that i'm coming across. I replied many pm's too but here is an example for those who still have confusions after reading my earlier topic on the new grade policy.

Assume there are 2 papers of subject X. P1 has 40 marks. And p2 has 60 marks. If in July CIE sets the minimum number of marks required for an A in p1 as 32/40 and for a B as 29/40. Likewise it sets A at 52/60 in P2 and B as 48/60 in P2. So, you need a minimum of this to achieve the required grade in each paper. Now, CIE will total your number of marks. One thing is for sure the minimum required to get A* will be set as many marks above the sum of the Grade A minimum as the grade B is below it. In this example:

for B: 29 + 48 = 77/100

FOR "A" 32 + 52 = 84/100.

Now CIE will subtract the minimum for a B from A.

Hence, 84-77 = 7 marks.

These will be added to the sum of A grade marks i.e. 84 + 7 = 91 marks. Therefore, 91/100 will be the minimum for an A*.

So, you can see it is not necessary to get a minimum in each paper. If you got say 31/40 in P1 it'll be given grade B according to our assumptions above. And if you got 60/60 in P2 you'll get an A in p2. But the total will be 31 + 60 = 91 marks. Hence, you've achieved the minimum for A* .

The minimum for A* that is 91/100 in our example will be mapped onto a percentage uniform mark of 90%.

The minimum for A in our example 84 will be mapped onto a percentage uniform mark of 80% .

Thats how it will work

Do you have a link where you got this information from?

 

[nightwalker221]

Did anyone of you give the exam for ESL
If you did, then how many marks do they cut if you write the article in continuous writing. As in you don't make paragraphs.

 

[Thampi4]

what was metal A, B and C for the question with the 3 graphs of metals


For me:
A was aluminium
B was magnesium
C was zinc

 

[AhmedMans]

If I remember correctly, the graph description is like this:
There's 3 lines, one of them goes less steep at first then gets more steep and finishes at more volume of hydrogen. I made it Aluminum as there's an oxide layer that prevents it from reacting fast at first as an explanation.
The other 2 have same volume of hydrogen but one of them was more steep. More steep is Magnesium, the other is zinc.

 

[nightwalker221]

Thats wrong!
The first was magnisium
second was aluminium
third was zinc
because the aluminum graph started off slow because it has an oxide layer on top of it.
Thats why.
For THAMPI4

 

[AhmedMans]

Thats wrong!
The first was magnisium
second was aluminium
third was zinc
because the aluminum graph started off slow because it has an oxide layer on top of it.
Thats why.

That's what I meant! I did it like that too!
*High five*

 

[Thampi4]

what was the graphs like

i dont remember

 

[Thampi4]

aluminium was the graph which had the most voilume right?

 

[Diidiie04]

aluminium was the graph which had the most voilume right?

yea as i think..

 

[AhmedMans]

aluminium was the graph which had the most voilume right?

Yes! Slow at first due to oxide layer, makes sense when you think about it.

 

[nightwalker221]

Cheers!
How was your mole question,
i messed it up
so damn CONFUSING!

 

[Thampi4]

then i wrote the right answer

 

[Diidiie04]

guys..remeber the queatina abt the 2 acids ...hydobromide and hydoide (or watever was its name)..wat dd u write as an ans of the ques in which chlorine gas was bubbled?? the reaults i mean.. :good: :wink:

 

[nightwalker221]

I wrote chlorine displaced both of them and Reddish brown gas evolved and A black ppt formed.
i hope its correct.

 

[AhmedMans]

About the moles question which was in the same question as the metals one, I didn't answer it... :/
But about the results of chlorine or whatever, I made one grey and the other one brown, I am 60% sure I'm wrong. Would be great if someone says anything.

 

[Diidiie04]

but isnt iodide soluble in nonpolar slvents?? how cud ba ablack precipitate?? i wrote brown gas 2..

 

[nightwalker221]

nop
it forms a ppt

 

[Diidiie04]

nop
it forms a ppt

how cud it form a ppt and its soluble ...the acid was a nonplolar solvent...so it defintley dissolved.....

 

[AhmedMans]

nop
it forms a ppt

Do I HAVE to write precipitate?
I made the first one : Grey colour
Second one: Brown colour

????

 

[Diidiie04]

nop
it forms a ppt

Do I HAVE to write precipitate?
I made the first one : Grey colour
Second one: Brown colour

????

it doesnt form a ppt..so grey colour and brown colour i think wud b the safest ans... :wink: