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Bonding in Liquids

  1. Apr 20, 2005 #1


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    I did an experiment and here are my results.

    Liquid Depth of vortex Time
    Paint thinner 2 lines (2.0 cm) 4 seconds
    Oil 1 line ( 1.0 cm) 2 seconds
    Water 3 lines ( 3.0 cm) 8 seconds

    1. Based on the results from the experiment I would say that paint thinner has Van der waal intermolecular bonding. Oil has dipole intermolecular bonding. And water has hydrogen bonding.
    2. Based on my findings oil was the fastest vortex to disappear. The vegetable oil is the thickest liquid and it slowed the fastest. With the oil being held together by dipole forces. Paint thinner was the second fastest vortex to disappear. Paint thinner was held together by van der waal force. Water had the longest vortex. The vortex lasted 8 seconds and was the deepest. Water is held together by strong hydrogen bonds.
    3. Water is so different in the time and depth because it has the highest viscosity and Strong hydrogen bonds.
    4. Sugar dissolves in water much faster than salt under the same conditions due to having weaker bonds.
    Do these answers sound right?
  2. jcsd
  3. Apr 21, 2005 #2
    I think my experience tells me that sugar dissolves more slowly than salt, but I'm not quite sure. But actually the salt may dissolve faster because of the hydration enthalpies of the ions. But this actually shouldn't explain the kinetics... :confused:

    1: I don't think oil is so polar. But I really don't know what a vortex is ;)
  4. Jun 16, 2005 #3
    I have done a similar experiment, and I still dont quite get it...

    I understand that hydrogen bonds are the strongest.. but what does that have to do with depth of the vortex or the amount of time it lasts?

    are we breaking bonds here? Why does the strongest bond have the deepest vortex and last the longest?
  5. Jun 16, 2005 #4
    Now knowing what the liquids are, I think it is more to do with the viscosity of the liquids.

    The Bob (2004 ©)
  6. Jun 16, 2005 #5
    yeah, but we havent learned anything about viscosity..

    I'm being asked to explain what happens in terms of intermolecular bonding :frown:

    hmmmm.....is there a connection between viscosity and intermolecular bonding? or are they totally seperate?
  7. Jun 16, 2005 #6
    Viscosity of liquids does with molecular structure and intermolecular bonding. Generally, if liquids have similar structure forms (chain or cyclic) and molecular weight, the viscosity increases in the order: Van der Waals liquids, polar liquids and H-bond liquids. water is an exceptaion and, often, it does not follow some regular rules of organic small molecuar liquids.
  8. Jun 16, 2005 #7
    Actually this is a pretty good question. First what are the likely interactions between oil molecules, paint thinner molecules (what is paint thinner ?), and water molecules ? How could a Van der waals force appear to be stronger than hydrogen bonding ? How could a dipole moment force appear to be stronger than hydrogen bonding ? And related question why is oil more viscous than paint thinner which is more viscous than water ?
  9. Jun 16, 2005 #8
    hmm well hopefully someone can explain this to me... otherwise I'll just have to make something up :frown: ,, lab is due tomorrow.

    I just dont think its viscosity, because we havent learned it, and I'm not expected to know that... its all about the intermolocular bonding
  10. Jun 17, 2005 #9
    How many hydrogen bonds can a molecule of water form ? How many van der waals "bonds" can a c12 hydrocarbon (oil) form ? Which molecular interaction would be stronger (think in terms of the sum of all potential interactions) ?
  11. Jun 17, 2005 #10
    I would still think that the hydrogen interactions are stronger, but again I dont know what the strength of bond or the strength of the molecular interaction has to to with it... i think thats my main problem,.. I'm not understanding the concept of the vortex and what its actually doing to the molecules..

    How can the strength of the bonds matter if no bonds are being broken?

    Or maybe bonds are being broken in a vortex?
  12. Jun 17, 2005 #11
    No bonds are being broken. DrMark is asking how many bonds can be formed.

    Bonds might move, like instantaneous dipole-induced dipoles forces (van der Waal's). Xenon atoms can form bonds but it could only be for a little while.

    The Bob (2004 ©)
  13. Jun 17, 2005 #12
    when we say that the intermolecular interaction in H-bond liquids is stronger than the other two, it should be referred to the 'force' per atom (C or O), rather than per molecule. I think the intermolecular interaction is stronger in oil than in water because there are much more atoms involved.
  14. Jun 14, 2006 #13
    the lab states, that the depression that forms when the liquid is stired is the vortex.

    oil was the fastest vortex to disappear

    sugar will generally disolve slower then salt.

    "...what does that have to do with depth of the vortex or the amount of time it lasts?"

    The stronger the bonds the more energy it takes to convert potential energy to kinetic energy... the more kinetic energy an object has the more active it is, and thus the better chance of it being liquid or gas... so if the stirring or addition of kinetic energy means that you are moving those atoms around, they just happen to be rolling over one other as energy is transfered from them colliding into one another. Now if you have more viscous or tighter bonds it doesn't move as easier because you need to apply more energy to move a tighter structure. It is like either splashing some water or trying to splash with a 1 meter cubed chunk of ice... you will most likely splash with the water easier. This is because the water has more kinetic energy and less potential energy. The icecube atoms/molecules are moving 'slower' because they have less 'heat' that heat is actually quantum energy at a microwave/infrared level. Vibrational enregy is at a certain osciolation of photonic or electromagentic energy, in tune with the overall movemoment of the matterenergy translation in the gravity well called the universe. That is energy as matter has structure and energy, that energy structure is moving as light in light in a direction in spacetime, the vibration is photons moving in different directions within the structure causing, 'heat' to form as there is an addition of energy at the location. So in terms of bonding, the stronger the bond the more energy exists 'contained' in a localized area. Depending on the electronegativity difference in the bond will say how much 'excess' energy is left in the structure to form a 'sheild' from other elements enetering deeper in the structure and causing it to 'vibrate' more, and thus change state or have energy to break the bond.

    When you stir a liquid "yes" you are "breaking bonds" not in the intramolecular forces, but between the molecules of the object so h2o-h2o to h20 + h2o just like if oyu take a cup of water out of a pool of water.. you are seperating the water inthe cup from the water in the pool.. this is done by 'kinetic energy. If the water was really viscous.. like molases.. which is a carbohydrate sacharide.. it would be more diffult to get that cup.. because the bonding is 'stronger' or tighter, has more density mass etc.. .. same with taffy.. or what about hot metal? etc..

    This is due to the energy holding the molecules of the liquid together. .you are not getting a cup of oxygen and a cup of hydrogen .. to do that would take the creation of a lot more energy.. if you stirred it really really fast.. you might get it.. but that may be a little beyond human capacity.. ust like you stirring the hydrogen so fast you got quarks etc..

    it takes energy.. but as energy approaches the speed of light time is said to relatively slow down.. or imposibly reverse. which may be useful in answering this question in time for you to compete the lab...

    "hmmmm.....is there a connection between viscosity and intermolecular bonding? or are they totally seperate?"

    They are the same generally.. it is the friction between objects. friction is based on the exchange of forces between atoms. It is imo essentially the same but it takes 'more' factors then just the bond strenghts.. i.e other forces... energy .. physics..

    "what is paint thinner" for the purpose of this experiment it is a hydrocabon methy benzene c6h5ch3 (toluene)
    Bond type Relative strength
    Ionic bonds 1000
    Hydrogen bonds 100
    Dipole-dipole 10
    London Forces (van der wals forces) 1

    Since oil is dipole dipole and paint thinner is van der was we see that oil is 10x stronger bond
    How many hydrogen bonds can a molecule of water form ? How many van der waals "bonds" can a c12 hydrocarbon (oil) form ? Which molecular interaction would be stronger (think in terms of the sum of all potential interactions) ?
    Hydrogen bonding is stronger then both london (van der wals) and dipole

    How can the strength of the bonds matter if no bonds are being broken?
    "Intermolecular bonds are being broken" unless when you stir the liquid it all moves together.. if you notice in the vortex.. there is a drag on the liquid.. notice how it keeps spinning after you stop stiring.. from when you stop until the vortex falls apart. that means that the bonds are all together again partially.. they will still move towards any ionic or charges unless you water is perfectly balanced.

    They are broken in the vortex, they are joined at the vortex. the vortex is the center of the forces, it is like a molecule there is spinning around and as it spins there are layers ontop of it that are spinning et vice versa.

    imo, if you add more kinetic energy to the water then you cause movement and convert potential energy to kinetic enrgy.

    my brain isn't working but I felt like adding to this question as it is in a workbook I am doing, and I like the idea of there being a database to assist future people that may get this question...

    this is my opinion and it is suggested you verify this information before you use it.

    The bonds were right imo
    1. the oil is the thickest with the most bonds, it takes more kinetic energy to cause it to move, so when stirring it didn't get moved as fast, not as much energy transfer.. it also had the smallest depth,so it naturall took less time to reform to a relatively inert form'
    the paint thnner and it's vande wals forces showed that the bonds were tight but not as tight as the oil. van der wals forces the electrons are moving but only slightly so it is like slowly breaking as the intermolecular firction caused by repulsion and attraction of elements moving around causes the movement to become 'standard'. The trend goes back to a constant of mass being pulled down by gravity as it attempts to conform to the shape of the container so this downwar force pulls the molecules raised by the vortex displacement back down giving 'less' space for movement away from a more stable bond interaction (must slower).
    the water has a relativey strong bond force however it's volume to mass ration or density is much lower then the other objects.. h2o .. and is at 104.5 degrees or something like that.. I'm not sure about mass to volume however my geuss there are many more water moleculres and they are lighter, and the bond is stronger.. so as they spin around they gain momentum faster.. because of the trend to continue moving they take a slightly larger ammount of time to slow down because the momentum is substracted from the velocity minus the angular momentum of gravity on the molecules.. essentially more are moving faster have more kinetic energy so it takes longer to direct this connectic energy amongst all the molecules. The more molecules the more collisions it takes to slow or stop it.

    So in case of the oil.. fewer collisions but heavier mass meant that it takes more force to gain accelleration of the kinetic energy f=m*a or a=m/f .

    far less force needs to be applied to the smalller massed atoms to have them accellerate and maintain a velocity against the force of gravity.

    3. water is a smal simpe molecule so it is easier to add kinetic energy to,

    4. that is a good question my guess is that it is based upon solubility which is the next unit.. I think though that it has to do with the bond stenghts NaCl is an ionic compound thus it is stronger then the sugar ? which is c6h12 or something like that for glucose etc.. this is a good question. Since sugar is said to disolve slower it appears to be sort of a trick question. not sure on this one yet.
  15. Jun 14, 2006 #14
    4.a non-ionic soluble substance will dissolve faster than an ionic soluble substance, because the forces holding the non-ionic substance is usually weaker than an ionic substance.
  16. Jun 14, 2006 #15
    salt NaCl is ionic
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