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

    13
    ReputationRep:
    For a substance to be soluble in water, does it have to be able to form hydrogen bonds or can it be soluble even though it only has van der waals and dipole dipole attractions?
    Offline

    2
    ReputationRep:
    (Original post by fullmetal heart)
    For a substance to be soluble in water, does it have to be able to form hydrogen bonds or can it be soluble even though it only has van der waals and dipole dipole attractions?
    If it's polar/ionic/permanent dipole, then it will be soluble.
    Offline

    3
    ReputationRep:
    Like dissolves like. So if two things are polar (or non-polar), they will most likely dissolve each other. So no, solubility is not only dependent on the formation of hydrogen bonds (but substances can dissolve by forming hydrogen bonds). As long as the interactions are the same, the solute is soluble. Overall, polarity is the main factor that effects solubility in water, as the solute must be polar.
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by champ_mc99)
    If it's polar/ionic/permanent dipole, then it will be soluble.
    I thought halogenoalkanes had a perminant dipole but the carbon - halogen bond wasn't polar enough for it to be soluble in water
    Offline

    2
    ReputationRep:
    (Original post by fullmetal heart)
    For a substance to be soluble in water, does it have to be able to form hydrogen bonds or can it be soluble even though it only has van der waals and dipole dipole attractions?
    In order for a solution to form, the intermolecular attractions between the solute and solvent must be greater than the attraction between solute molecules or the attraction between solvent molecules.
    eg: two polar molecules will generally be soluble as they have permanent dipole-dipole forces exist between the H atoms with the Cl and Na with O as in NaCl and H2O.
    Offline

    2
    ReputationRep:
    (Original post by fullmetal heart)
    I thought halogenoalkanes had a perminant dipole but the carbon - halogen bond wasn't polar enough for it to be soluble in water

    Thats because halogenoalkanes are likely to have stronger van der waals forces between them unless it is a branched halogenoalkane.
    Offline

    2
    ReputationRep:
    (Original post by fullmetal heart)
    I thought halogenoalkanes had a perminant dipole but the carbon - halogen bond wasn't polar enough for it to be soluble in water
    It is polar enough. That's how you get substitution reactions: the haloalkane is dissolved in water.
    • Community Assistant
    • Study Helper
    Online

    14
    ReputationRep:
    Community Assistant
    Study Helper
    Solubility, or rather miscibility, depends on a three-way struggle.

    1. There are bonds between liquid A molecules
    2. There are bonds between liquid B molecules
    3. There are bonds between liquid A and liquid B molecules

    For something to be soluble it has to form bonds strong enough to disrupt the bonding in the two pure phases, otherwise each component keeps itself to itself.

    Haloalkanes can form polar bonds to ethanol which are strong enough to disrupt the H-bonding in ethanol, but its weak polar bonding to water is not strong enough to disrupt the stronger H bonding in water.
 
 
 
  • 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
    Brussels sprouts
  • 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

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