Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    I've got to write a planning exercise 4 the question To determine the formula of hydrated sodium carbonate Na2CO3.xH2O

    When hydrated sodium carbonate is heated,the water of crystallisation is lost and the solid becomes anhydrous.
    Plan and describe two experimentral methods for determining x,the number of moles of water of crystallisation in 1 mole of hydrated soduim carbonate.

    The first method must involve heating crystals of hydrated sodium carbonate.
    The Second methods should involve a titration.

    how should i set it out and what chemical knowledge must i put in it

    any help useful or any1 else stuck on it
    Offline

    1
    ReputationRep:
    urm well here are the two perfect methods (we did this experiment for the evaluation and analysis skill) i dont know if it will help but anyways, here we go:

    Method 1:
    1. Using a balance that weighs to two decimal places, weigh a crucible. Add between 1.30 – 1.50 g of hydrated iron II sulphate crystals. Record the masses.
    2. Place the crucible containing the hydrated iron(II) sulphate crystals on the pipe-clay triangle and gently heat for about two minutes. The heating should be carried out in either a fume cupboard or a well-ventilated room.
    3. Allow to cool and weigh the crucible and the iron(II) sulphate.
    4. Repeat steps 2 and 3.
    5. Record all of the masses.
    Method 2: Titration
    1. Weigh as accurately as possible between 2.85 and 3.10 g of hydrated iron(II) sulphate crystals, FeSO4.xH2O. Record the mass and then dissolve the crystals in 50.0 cm3 of 1 mol dm-3 H2SO4(aq) and make up to 250 cm3 in a volumetric flask with distilled water. Invert the volumetric flask several times to ensure that the solution is evenly mixed.
    2. Using a pipette filler, pipette 25.0 cm3 of the solution of iron(II) sulphate into a conical flask and add approximately 20.0 cm3 of the 1 mol dm-3 H2SO4(aq) solution provided.
    3. Titrate the acidified Fe2+(aq) solution with 0.0100 mol dm-3 potassium permanganate, KMnO4(aq), and continue the titration to the normal end-point.
    4. Repeat the titration until you have obtained concordant results
    Offline

    0
    ReputationRep:
    hi there
    yh those should be the methods of how to do the experiment what about the calculations how would they be done and set out
    reply bck thanks
    Offline

    2
    ReputationRep:
    for method 1, how do you know to use that amount of crystals do use? and do you mean to weigh every 30 seconds?
    Offline

    0
    ReputationRep:
    When using the crucible, would you heat it with or without the lid on? Would you do it with the lid on to keep the heat in, then after a while with the lid off so the water vapour escapes?

    Just a thought...
    • CV Helper
    Offline

    18
    ReputationRep:
    CV Helper
    there's another thread,

    but you should heat with the lid on.
    measure and use any amount of crystals you want. and no you don't weigh every 30secs. you weigh after heating,after it has cooled.

    there's another thread with more detailed answers there.
    Offline

    5
    ReputationRep:
    (Original post by Tabs)
    hi there
    yh those should be the methods of how to do the experiment what about the calculations how would they be done and set out
    reply bck thanks
    for method 1...
    firstly you calculate the mass loss (and that would be the mass of water in the hydrate)
    then using the formula moles=mass/mr you find the number of moles...
    but i'm still stuck with the titration calculation... any help will be much appreciated!
    Offline

    0
    ReputationRep:
    omg!
    i just my plannng exercise through the post.
    what do you do?

    i hate my teacher!! he doesnt help me.

    please can someone help me on how to carry out this planning exercise..

    what is the crucible?
    • CV Helper
    Offline

    18
    ReputationRep:
    CV Helper
    (Original post by suzukiescudo)
    omg!
    i just my plannng exercise through the post.
    what do you do?

    i hate my teacher!! he doesnt help me.

    please can someone help me on how to carry out this planning exercise..

    what is the crucible?
    you sure you do chem? you don't know what a crucible is?

    go check the other thread.
    Offline

    16
    ReputationRep:
    Method 1 seems straightforward, how does method 2 work? The hydrated bit, how to make that significant and 'calculatable' in a titration? How does the titration described help to us to determine x?
    Offline

    0
    ReputationRep:
    you sure you do chem? you don't know what a crucible is?
    okay now i have chemistry lessons at evening classes thats mondays only, 6 till 9:30p.m.

    the teachers rubbish!

    im lost here, wheres the other thread?
    Offline

    0
    ReputationRep:
    whats the layout of everyones plan because im like what do i start with this planning activity.

    where do you start?
    Offline

    0
    ReputationRep:
    can some1 give me the link to the other thread please?
    i cant find it!!!
    Offline

    0
    ReputationRep:
    whats the layout of everyones plan because im like what do i start with this planning activity.

    where do you start?
    I've done
    background info - with the definition of water crystallisation and the values x can take
    method one - apparatus, diagram, method, calculations
    method two - apparatus, diagram, method, calculations
    safety
    references

    I have no idea where the other thread is I can't see it
    Offline

    0
    ReputationRep:
    i found the other thread a couple of days back but it didnt sem to have that much in it.

    has everyone done the two methodays completely seperately or have they done them togeter, ie, Method- 1, 2, apparatus- 1, 2, calcs- 1, 2, etc?
    Offline

    0
    ReputationRep:
    the way the question is set out, my interpretation is that you have to do it seperatly. at least i have!
    out of curiosity, what are people getting X to equal?
    i am thinking 8ish???
    Offline

    0
    ReputationRep:
    i havnt got a clue whats goin on with this coursework! i could do with some serious help... and im looking for an A grade! i cant believe i dont know whats going on!
    somebody help me... ok, i have an idea of how to lay it out, but i dont know what to include in the background knowledge... and i dont understand the titration method in order to find out X... and the calculations... i havent got a clue!
    i have to hand it in to my teacher on wednesday, and its monday! anyone got a link with EXTENSIVE help? i've never been too good at coursework anyways!
    Offline

    5
    ReputationRep:
    The whole thing is confusing me!!! how could we use titration to find the number of moles of water in the halide? OK... i know that there is some help on this thread on the procedures to be followed but what are the calculations necessary man? and i have to hand in the whole thing on Friday! On top of all this, I got a physics planning exercise to do... God save me!!!
    Offline

    0
    ReputationRep:
    the way the question is set out, my interpretation is that you have to do it seperatly. at least i have!
    out of curiosity, what are people getting X to equal?
    i am thinking 8ish???
    i got 8!
    PM me i wana see if we got the write calculations!
    dont wana take the fun away from everyone.....
    Offline

    0
    ReputationRep:
    just to start:

    Balanced equation:
    Na2CO3 + 2HCl --> 2NaCl + H2O + CO2
    1 mole 2 moles 2 moles 1 mole 1 mole

    is this the balanced equation?

    some1 please corect moi, i am rubbish at this balancing thing!

    has everyone done the two methodays completely seperately or have they done them togeter,
    yup, i will be doing it seperate.
    dont wana got it muddled up!
 
 
 
Turn on thread page Beta
Updated: April 6, 2008

2,743

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should predicted grades be removed from the uni application process

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.