The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

Cie atp chemistry 2016

Exam is tomorrow :s-smilie: i seem to only have trouble with the last questions on investigations/experiments.There is usually a clue to the questions but they arent my thing :s-smilie: i just know titration and displacement reaction is there any way i could do somewhat good in those questions i have my exam tomorrow :frown: a quick response would be helpful

Scroll to see replies

Original post by Abdullah IGCSE
Exam is tomorrow :s-smilie: i seem to only have trouble with the last questions on investigations/experiments.There is usually a clue to the questions but they arent my thing :s-smilie: i just know titration and displacement reaction is there any way i could do somewhat good in those questions i have my exam tomorrow :frown: a quick response would be helpful


Hi! I moved this to the Chemistry forum for you - you're more likely to get an answer here :smile:
Original post by Abdullah IGCSE
Exam is tomorrow :s-smilie: i seem to only have trouble with the last questions on investigations/experiments.There is usually a clue to the questions but they arent my thing :s-smilie: i just know titration and displacement reaction is there any way i could do somewhat good in those questions i have my exam tomorrow :frown: a quick response would be helpful

funny because planning a titration was a 6 marks question there.
Reply 3
Avatar for laveeza
laveeza
2
Original post by 15demon
funny because planning a titration was a 6 marks question there.


do you know the answers i have given it today can you tell me the answers ??
what was the apparatus that you named? beaker and stand? and what was the colour of the sodium sulfite?
Reply 5
Avatar for laveeza
laveeza
2
Original post by chemistry igcse
what was the apparatus that you named? beaker and stand? and what was the colour of the sodium sulfite?

yeah beaker and stand and white colour ....i knew it was white but i didnt read carefully and wote silverish white that of sodium !
i wrote colourless :frown:
and what was the purpose of the starch, the advantage and disadvantage of the pipette?
Reply 8
Avatar for laveeza
laveeza
2
Original post by chemistry igcse
and what was the purpose of the starch, the advantage and disadvantage of the pipette?


starch acts as an indicator what you wrote about pipette?
The exam was relatively easy :smile: i wrote the last part in bullet points this is what i wrote:

1-put 100cm^3 of sulfuric acid into a beaker
2-add an indicator(methyl orange or litmus paper)
3-add solution of potassium hydroxide until color change in indicator(use burette)
4-note down the amount required for color change
5-evaporate solution to dryness
6-wash and dry crystals

and i think the purpose of starch was a catalyst that speeds up the reaction :smile:.For disadvantage i wasn't sure but i wrote that it takes time to do and requires precise movements for accurate volume of hydrogen peroxide or sodium thiosulfate if i remember.For the tests i wrote shiny white for appearance and no change for 1st observation and second observation was sulfur dioxide gas produced and tests on solid F i wrote that the gas was ammonia and ammonia ions were present and also wrote yellow flame color for sodium
(edited 7 years ago)
Original post by 15demon
funny because planning a titration was a 6 marks question there.


Demon i was frightened of other investigations like finding the mass of a compound and percentage and the other types ive seen in past papers so i was quite frightened those would come in the exam so im glad they didn't but i feel as if the theory exam and multiple choice questions will be hard..
Reply 11
Avatar for laveeza
laveeza
2
Original post by Abdullah IGCSE
The exam was relatively easy :smile: i wrote the last part in bullet points this is what i wrote:

1-put 100cm^3 of sulfuric acid into a beaker
2-add an indicator(methyl orange or litmus paper)
3-add solution of potassium hydroxide until color change in indicator(use burette)
4-note down the amount required for color change
5-evaporate solution to dryness
6-wash and dry crystals

and i think the purpose of starch was a catalyst that speeds up the reaction :smile:.For disadvantage i wasn't sure but i wrote that it takes time to do and requires precise movements for accurate volume of hydrogen peroxide or sodium thiosulfate if i remember.For the tests i wrote shiny white for appearance and no change for 1st observation and second observation was sulfur dioxide gas produced and tests on solid F i wrote that the gas was ammonia and ammonia ions were present :smile:

100 cm3 is alot ........ i guess and it acts as a indicator which turns blue black when iodine is present .observation was that puple potassium manganate turns colorless as sulfurdioxide was produced.......for pipette i am not sure as i wrote that pipette takes up fixed volume (10-25cm3) and 3 cm3 was used thaere can be problem in taking the exact volume of solution
they never ask for a specified amount laveeza personally im confident the only parts i feel i could lose marks would be at the advantage of pipette and the observation on sulfuric acid the rest im pretty confident about :smile:
Original post by laveeza
100 cm3 is alot ........ i guess and it acts as a indicator which turns blue black when iodine is present .observation was that puple potassium manganate turns colorless as sulfurdioxide was produced.......for pipette i am not sure as i wrote that pipette takes up fixed volume (10-25cm3) and 3 cm3 was used thaere can be problem in taking the exact volume of solution

what are you talking about about iodine??
Reply 14
Avatar for laveeza
laveeza
2
Original post by Abdullah IGCSE
what are you talking about about iodine??

the potassium iodide's (ion coverts to atom ) iodide ion into iodine ...........the starch test for iodine shows a blue black colour when the result is postive !!!!!!
the starch was indicator. in your experiment you forgot to write "repeat experiment without indicator"
(edited 7 years ago)
it was not ammonia ions present, it was ammonium (NH4) ions
laveeza is right about the pipette
Reply 18
Avatar for laveeza
laveeza
2
Original post by chemistry igcse
the starch was indicator. in your experiment you forgot to write "repeat experiment without indicator"


ok let me clarify starch was for sodium thiosulfate question and i wrote reapeat without indicator in that last qusetion !!!!!!
btw sulphur dioxide produced is not an observation, its a conclusion. you had to write that potassium manganate turns purple to colourless

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you