Hey there! Sign in to join this conversationNew here? Join for free
    • Study Helper
    • Thread Starter
    Offline

    17
    ReputationRep:
    Study Helper
    Describe the differences in behaviour when magnesium chloride and silicon (IV) chloride are added sperately to cold water.
    You should include:
    The pH of any resulting solution
    relevant chemical equations
    experimental observations
    the name of the process taking place

    I can't find any places to revise this, is it something to do with charge density?
    Offline

    11
    ReputationRep:
    (Original post by Eloades11)
    Describe the differences in behaviour when magnesium chloride and silicon (IV) chloride are added sperately to cold water.
    You should include:
    The pH of any resulting solution
    relevant chemical equations
    experimental observations
    the name of the process taking place

    I can't find any places to revise this, is it something to do with charge density?
    http://www.chemguide.co.uk/inorganic...chlorides.html
    Offline

    9
    ReputationRep:
    In both the cases the cations undergo hydrolysis to give H+ ions and hence pH decreases. The resultant pH depends on the amount of chloride and water used. It is advisable to use very cold water in case of SiCl4. Add the chloride to very cold water slowly.
    • Study Helper
    • Thread Starter
    Offline

    17
    ReputationRep:
    Study Helper
    Thanks, but the guide didn't really explain it well for aluminium chloride or silicon chloride. Is it covalently bonded? I don't understand
    Offline

    11
    ReputationRep:
    (Original post by Eloades11)
    Thanks, but the guide didn't really explain it well for aluminium chloride or silicon chloride. Is it covalently bonded? I don't understand
    http://revision-notes.co.uk/Detailed/1076.html

    bonding can be a bit complicated to understand sometimes, but as long as you are aware of electronegativity difference resulting in polarisation of charge density => slight ionic character amongst covalent molecules and in contrast when you have small cations, large anions => this tends to give you polarisation of charge clouds in ionic molecule.

    the idea is that covalency can arise in ionic molecules, and vice versa too. a lot of bonding is simply described in terms of the predominant type.
    • Study Helper
    • Thread Starter
    Offline

    17
    ReputationRep:
    Study Helper
    (Original post by shengoc)
    http://revision-notes.co.uk/Detailed/1076.html

    bonding can be a bit complicated to understand sometimes, but as long as you are aware of electronegativity difference resulting in polarisation of charge density => slight ionic character amongst covalent molecules and in contrast when you have small cations, large anions => this tends to give you polarisation of charge clouds in ionic molecule.

    the idea is that covalency can arise in ionic molecules, and vice versa too. a lot of bonding is simply described in terms of the predominant type.
    Thanks a lot
    Offline

    9
    ReputationRep:
    (Original post by Eloades11)
    Thanks, but the guide didn't really explain it well for aluminium chloride or silicon chloride. Is it covalently bonded? I don't understand
    SiCl bond is covalent whereas MgCl bond is more ionic. The reason is polarizability difference
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Has a teacher ever helped you cheat?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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.