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Last minute chem 33 info!!!!

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"Practical consists of 3 questions.. Titration, identification of ions, heating,
1. Identification of ions :
carbonate,ammonium or bromide.
Two powders will be provided to you. Take them in two beakers separately, dilute them by adding water, then take few amount of sol. Of both in test tubes. Add h2so4 or hno3 in that . Brisk effervensece wil be observed. Proving that one contains carbonate.
Take the other one. Heat it.. Gas evolved turning red litmus blue... If not then do test for bromide by adding AGN03. CREAM PPT...

2ND EXPERIMENT :
heating ... Note the weight of compound given... Hydrate it into form of sol. (they will tell u how to hydrate it) ... Heat it for some time... A gas will be evolved... That gas is co2.. Measure weight again. Heat again. Measure weight again until the weight becomes constant. Then calculate the percentage of impurity...

Experiment 3:
titration with KMnO4!
Have shughal!
 
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Np I'm just a candidate like you posting any info i get! This is NOT 100% alrighty :p it matches info my teacher gave!
 
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Thanks Fellguud77 ! Can you please tell a past year question which is similar to experiment 2
 
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Dont really know past question :p but Oct/Nov 2002 will suffice as good practice!
 
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As in 33? I've seen wooden wedges in my school center lab and new rulers :p
It's gonna be a moments of forces experiment, two wedges( double pivot ), scale with unknown masses on top.
The second question has oscillation coming, something involving paper, clips, a bulldog clip etc.
 
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by masterboss365 » Wed May 11, 2011 5:08 pm
Tritration with KMnO4, sodium thiosulfate, potassium iodide
J07/32, J08/31, N08/32,

Heating related question. Find water of crystallisation. Heating (may be CuSO4 hydrated ) and then finding mass of water lost. Check for percentage of water present. J08/32, J09/32,

Salt anylsis
NH4+, Br-, NO3-, CO32-,
ammonium sulfate, zinc nitrate, ammonium bromide


Thanks,
Not sure 100%.
 
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Tips for Titrations:

First of all, there is an equation given, and you have to find the moles of one of the substances taking the equation in mind.
Titration involves acid and bases, and the fact that when appropriate amount of each acid and base react, they form a Nuetral Solution.

They will tell you every step you have to do..
Just read it carefully, dont be confused, and follow each step they tell you accurately.

You use a Indicator to help you find out what is the end point. the End Point is the point when all acid has reacted with all of the base.

You have either one in the burette, and the other one in the flask below. You open the burette, and when the endpoint is reached you close it. Near the endpoint , one drop from the burette will change the indicator colour. The value of the burette is called Titre Value.
They expect you to make a table, it has 6 Marks, and 2 of them for Making a Table!!.
Table should include
1st Titre 2nd Titration
Initial Burette Value
Final Burete Value'
Volume Used:
You record Titre Values 2-3 times to confirm accuracy. You then choose the 2 most closest titre values, and take out their average. they should be within 0.1cm^3.

Then you use your basic mole concept to solve the mole questions after that. They will tell you what you need to find out, and you will have to use your mole knowledge, and your titre value. You need to be sharp at moles for this question, as there are many confusing questions which require good knowledge of the Moles.
 
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