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OCR Chemistry - Why does H2S have a lower boiling point than H2Se? Watch

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    I understand that H2O has a higher boiling point than H2S because it forms Hydrogen Bonds between its molecules which are strong.
    BUT why does H2S have a lower boiling point than H2Se?
    I thought they were both polar molecules in which case surely they form permanent dipole forces?
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    (Original post by glastonbury)
    I understand that H2O has a higher boiling point than H2S because it forms Hydrogen Bonds between its molecules which are strong.
    BUT why does H2S have a lower boiling point than H2Se?
    I thought they were both polar molecules in which case surely they form permanent dipole forces?
    Go to the periodic table ,look at Se and S,see which one has more electrons and then think about London forces.
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    Okay, but why induced dipole (london) forces? Surely if they are polar molecules they form permanent dipole forces?
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    (Original post by glastonbury)
    Okay, but why induced dipole (london) forces? Surely if they are polar molecules they form permanent dipole forces?

    The electronegativity difference is too small.
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    (Original post by glastonbury)
    Okay, but why induced dipole (london) forces? Surely if they are polar molecules they form permanent dipole forces?


    The electronegativity difference is too small.
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    (Original post by glastonbury)
    Okay, but why induced dipole (london) forces? Surely if they are polar molecules they form permanent dipole forces?
    It is very important to know that permanent dipoles occur in addition to London forces not instead! Also the bigger the atom the higher the London forces.
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    im so confused. is the bpt of h2se higher than h2s because h2se has a higher electronegativity?
 
 
 
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