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Chemistry: Post your doubts here!

Discussion in 'International A And AS Level' started by XPFMember, Sep 29, 2011.

  1. XPFMember

    XPFMember XPC Moderator Staff Member

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    Hi everyone, AsSalamoAlaikum Wr Wb..

    To get things organized in a better way, I am making this thread. As othewise, some queries remain unanswered!

    So post your CHEMISTRY doubts in this thread. InshaAllah members around will help you.

    Any Chemistry related notes and links will be added here in this post. Feel free to provide the links to your notes around the forum, or any other websites!

    Chemistry Notes:


    http://www.chemguide.co.uk This is the website, which contains almost everything classified according to the syllabus.

    Tips for solving chemistry MCQs 9701/01

    Chemistry P5 Tips and Notes

    Some links & Notes - by 'destined007'

    Chemistry worksheets Link shared by hassam

    Chemistry Application Booklet: Mistakes and Corrections!

    Calculations for A level Chemistry, author E.N. Ramsden third edition ebook download.


    Regards,
    XPC Staff.
     
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  3. hassam

    hassam

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  4. XPFMember

    XPFMember XPC Moderator Staff Member

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    Assalamoalaikum!! :)

    first post updated!
     
  5. hassam

    hassam

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    A 20.0mL sample of 0.200M HBr solution is titrated with 0.200M NaOH solution. Calculate the pH of the
    solution after the following volumes of base have been added:
    15 mL
    ANYBODY ????
     
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  6. hassam

    hassam

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    A 35.0mL sample of 0.150M ethanoic acid, is titrated with 0.150M NaOH solution. Calculate the pH
    after the following volumes of base have been added: 17.5 mL
     
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  7. AAestar

    AAestar

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    I am going to give it a try.

    Moles HBr = 0.020 L x 0.200 M =0.0040
    Moles NaOH = 0.015 L x 0.200 =0.0030

    Moles H+ in excess = 0.0010
    Total volume = 0.015 L
    Concentration H+ = 0.0010 / 0.015 =0.0667
    pH =-log ( 0.06667)
    =0.176
     
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  8. yubakkk

    yubakkk

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  9. yubakkk

    yubakkk

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  10. hassam

    hassam

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  11. ching293

    ching293

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    Nov 2007 paper4 question 3, CIE

    since Cl2 is more +ve, isnt it suppose to undergo reduction? why is the equation the other way round from what i did :)
     

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  12. memyself15

    memyself15

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    yeah, chlorine should gain electrons since it's E* value is more positive.
    lets see what xpf member says
     
  13. XPFMember

    XPFMember XPC Moderator Staff Member

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    Assalamoalaikum!! :)

    I'm not sure about this question, but according to what I understand, dichromate is an oxidising agent! So it'll oxidise the CL- ion?! :unknown: does that make sense?
     
  14. yubakkk

    yubakkk

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    where is the discussion of paper 1 and 2 of chemistry??
     
  15. ching293

    ching293

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    thats what my classmate told me too, i am not sure, but i guess i'll stick with it. Thanks!
     
  16. OakMoon!

    OakMoon! XPC Moderator Staff Member

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    You may discuss them here.
     
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  17. princesszahra

    princesszahra

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    Every reaction can proceed in heither direction!!but the probability of each of them is different!! so it can either undergo reduction or oxidation( specific conditions!)
     
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  18. XPFMember

    XPFMember XPC Moderator Staff Member

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    I'll check with my teacher again! I was about to ask today but I couldn't remember which year it was in :oops:
     
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  19. hassam

    hassam

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    explain trend of solubility of group 2 sulphates.....well in anser to this.....we have to write that hydration enthalpy decrese faster than lattice bt i dont undrstnd how
     
  20. Newbie

    Newbie

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!

    These sites might help ... check em

    1.Beta-Theta.com Chemistry Section
    http://adf.ly/378ET
    Notes on a number of topics relevant to AS/A Level Chemistry are included. The notes include a particularly good interactive Periodic Table. There is also access to Homework Help and to a Midnight Café chat-room.

    2.http://adf.ly/l8tn
    This is a US site intended for first year undergraduates, but much is relevant to AS/A Level Chemistry. Notes, articles and tutorial are included. A number of experiment simulations can be accessed. The compound library is very good.

    3.http://adf.ly/l8to
    A lighthearted look at many aspects of Chemistry. There are a lot of links to useful pages written by teachers and students. Not all of this is relevant to AS/A Level, but much is. A wealth of information and a lot of fun.

    4.Chemsoc Interactive Periodic Table
    http://adf.ly/l8tp
    A high quality interactive Periodic Table with photographs and information about each element.
     
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  21. hassam

    hassam

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    Re: All Chemistry help here!! Stuck somewhere? Ask here!


    jaldi btao....i calculated bt not confident wid ma anser
     

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