Chemistry Paper 33 Purity% answer of CaCO3 and what were the metal and anions

[iKhaled]

No, the tables are fine: you may use a pencil for any diagrams, tables, graphs or rough working.
But other then that: not allowed.

phewwwwwww i almost had a heart attack lol i though these also r not allowed..

 

[sammykhan123]

abt iodine is any1 sure coz i was gettin cream ppt n not only me some of ma frnds were also gettin da same

I also got cream ppt and wrote bromide...and some others also got the same ....

 

[msohiabch]

No, the tables are fine: you may use a pencil for any diagrams, tables, graphs or rough working.
But other then that: not allowed.

even the the observation tables already given???
in the ion tests??

 

[littlecloud11]

I also got cream ppt and wrote bromide...and some others also got the same ....

yes the ppt was cream. iodide give quite a bright yellow ppt, so i'm pretty sure the ion was bromide. =)

 

[OakMoon!]

yes the ppt was cream. iodide give quite a bright yellow ppt, so i'm pretty sure the ion was bromide. =)

No. It has been confirmed by my teacher that it was iodide. And it was in no way cream. It was pale yellow colour but sadly not as bright as it usually is. You should have checked with Lead Nitrate too. That would have confirmed. Plus, the precipitate was not soluble at all in NH3. There is a different observation for sparingly soluble.

 

[Pals_1010]

No. It has been confirmed by my teacher that it was iodide. And it was in no way cream. It was pale yellow colour but sadly not as bright as it usually is. You should have checked with Lead Nitrate too. That would have confirmed. Plus, the precipitate was not soluble at all in NH3. There is a different observation for sparingly soluble.

That's so unfair.... I was having doubts about the colour of the ppt when I tested with Silver Nitrate and When I asked for lead(II) nitrate from the invigilator, he told me I was not allowed to use additional reagents.... So I wrote Bromide :'(

 

[Aarjit]

>>FA1 titres ~ 24.50 cm^3 and 18.50 cm^3
>>%purity of limestone ~ 75%
>>Reaction in a(iii): Redox [I-(aq) gets oxidized, simultaneously reducing Mn(VII)]
>>Oxidation states of Mn: +2 and +4
>>halides: Cl-(aq) and I-(aq)*
>>Observation on adding HCl(l) to Cu(II)SO4 ~ blue solution decolorizes to give a sap-green coloration.

*[Pb(NO3)2 was not required, but if you used it as a deterrent, I hope you didn't mention it in the paper: NO ADDITIONAL CONFIRMATORY TESTS]

 

[OakMoon!]

That's so unfair.... I was having doubts about the colour of the ppt when I tested with Silver Nitrate and When I asked for lead(II) nitrate from the invigilator, he told me I was not allowed to use additional reagents.... So I wrote Bromide :'(

I didn't even have time to check with Lead nitrate. But I was assured when the precipitate didn't dissolve even a bit.

 

[Pals_1010]

I didn't even have time to check with Lead nitrate. But I was assured when the precipitate didn't dissolve even a bit.

Well my bad luck... There will be ecf for the next part? If I wrote Br-, then my observation will be different with conc. H2SO4

 

[Aarjit]

I did my practical exam in pencil! Would it make any difference?

You must be kidding me! How can you be so blasé, Whocares*?

*no pun intended.

The invigilators in my center called all those who answered in graphite back and made them trace each and every word in their papers with ink. CIE standards and policies: utter fiasco!

 

[aom]

I did my practical exam in pencil! Would it make any difference?

I don't think it will make any difference as long as the examiner can see what you wrote...... the point of the exam is not to see if u can write with a pen, it is to test your knowledge.

 

[OakMoon!]

Well my bad luck... There will be ecf for the next part? If I wrote Br-, then my observation will be different with conc. H2SO4

Obviously!

 

[Aarjit]

I don't think it will make any difference as long as the examiner can see what you wrote...... the point of the exam is not to see if u can write with a pen, it is to test your knowledge.

READ THESE INSTRUCTIONS FIRST
9701/33

Write your Centre number, candidate number and name on all the work you hand in.
Give details of the practical session and laboratory where appropriate, in the boxes provided. Write in dark blue or black pen.
You may use a soft pencil for any diagrams, graphs or rough working.

P.S. Cambridge makes FIVE xerox copies of your paper prior to correction. They mark [R] for answers in graphite.

 

[aom]

READ THESE INSTRUCTIONS FIRST
9701/33

Write your Centre number, candidate number and name on all the work you hand in.
Give details of the practical session and laboratory where appropriate, in the boxes provided. Write in dark blue or black pen.
You may use a soft pencil for any diagrams, graphs or rough working.

P.S. Cambridge makes FIVE xerox copies of your paper prior to correction. They mark [R] for answers in graphite.

From where did u get this please ?? I mean the P.S thing

 

[Aarjit]

From where did u get this please ?? I mean the P.S thing

That, my friend, is a verbal excerpt from a skirmish between my friend and her Chem teacher when she got a 0/40 in her 9701/33 mock examination.

 

[Aarjit]

That, my friend, is a verbal excerpt from a skirmish between my friend and her Chem teacher when she got a 0/40 in her 9701/33 mock examination.

and yes, her paper was done in pencil.

 

[aom]

and yes, her paper was done in pencil.

Okay, but i wrote all my Biology paper 33 AS in pencil what should i do???

 

[Aarjit]

Okay, but i wrote all my Biology paper 33 AS in pencil what should i do???

I really don't think you can do anything about it now. When CIE sends you your SoR, bid for re-evaluation stating that your pen's gel-ink gradient was balked after you attempted to dye the highly-obscured-plasmolysed-onion-cells with it.
Worrying now is futile. Rule your 9700/42!

 

[littlecloud11]

That's so unfair.... I was having doubts about the colour of the ppt when I tested with Silver Nitrate and When I asked for lead(II) nitrate from the invigilator, he told me I was not allowed to use additional reagents.... So I wrote Bromide :'(

I asked for lead nitrate too, and the invigilator replied the same. This really isn't fair. >.<

 

[mujtabashahnawaz]

Titration values : 25 and 22 sth.
%age purity: around 75%
Anions: Iodide and Chloride
Oxidation states: +2 and +4