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    One of my homework questions is:

    Thin streams of some liquids are attracted towards a charge rod, but with other liquids there is no effect.

    a) Explain why some liquids are attracted while others are not?

    b) Predict which of the following liquids are deflected towards a charged rod and explain your predictions: water, hexane, bromoethane, tetrachloromethane.

    c) Why are the affected liquids always attracted towards the charged rod and not repelled?

    Please dont give me the answers, i need to understand where to start :confused: Im sure this has something to do with dipole moments but the problem is i still dont understand what dipole moment is :o:

    Thank you.
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    I'd look at what atoms you have in a bond and see which of them are electronegative and which ones are not. Do you understand the concept of permenant diples and instantaneous and induced dipoles?

    Does it say what charge the rod is? (+ve or -ve?)
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    (Original post by amani-puresapphire)
    One of my homework questions is:

    Thin streams of some liquids are attracted towards a charge rod, but with other liquids there is no effect.

    a) Explain why some liquids are attracted while others are not?

    b) Predict which of the following liquids are deflected towards a charged rod and explain your predictions: water, hexane, bromoethane, tetrachloromethane.

    c) Why are the affected liquids always attracted towards the charged rod and not repelled?

    Please dont give me the answers, i need to understand where to start :confused: Im sure this has something to do with dipole moments but the problem is i still dont understand what dipole moment is :o:

    Thank you.
    You need to look at which of the liquids are polar . They will be polar if there is an overall separation of charge and the permanent dipoles don't cancel each other out.

    For water, hexane, bromoethane and tetrachloromethane you need to see which are polar liquids. If they are they will be deflected by the charged rod.
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    a)SInce some liquids are charhed and others not charged(Polar and non-polar) so they are attracted or not.
    b)Water is attracted as its polar while hexane is not as its non-polar while bromoethane is also attracted but tetrachloromethane will not as its non-polar.
    c)The charged rod can set up induced poles in the molecules of the liquid and lead to small deflections with molecules which possess no permanent dipole so always the liquid is deflected.
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    Okay thanks guys.
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    (Original post by Loz17)
    I'd look at what atoms you have in a bond and see which of them are electronegative and which ones are not. Do you understand the concept of permenant diples and instantaneous and induced dipoles?

    Does it say what charge the rod is? (+ve or -ve?)
    Umm no i don't know the difference between those and it doesn't specify the charge on the rod.
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    (Original post by amani-puresapphire)
    Umm no i don't know the difference between those and it doesn't specify the charge on the rod.
    OK, I don't want to confuse you then as it might just be difference in teaching. It looks like you've got the answer now
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    Could you explain to me the concept of permanent dipoles and dispersion forces? In which bond are they found and what info about the bond do i get?
 
 
 
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