albertlee Posted November 3, 2004 Posted November 3, 2004 As stated in the title, my main focus is on the comparison of bonding in solution and compound, and what is the difference of solution and compound....or is a solution a compound?? Just take one example, when salt is dissolved in water, why the solid phase is broken down by water? What does this look like??? and how this structure make electrons of each of the element in salt free to conduct electricity??? thx for any respond Albert
Primarygun Posted November 3, 2004 Posted November 3, 2004 what is the difference of solution and compound....or is a solution a compound?? Actually, solution is a mixture. Compound has two or more element joined chemically together. I am going to talk about it. When you boil the solution, salt is found and steam goes away. Hence, you know no new substance is formed during the dissolving process. why the solid phase is broken down by water? Water molecules attract ions which are hold by strong ionic bond together in the solid. Several water molecules are enough to overcome the attraction. The ions then leave the solid and go into water. What does this look like? If we ignore the water dissociation, Water molecules contain some ions. For the presence of precipitate, it depends on the solubility of the solute. how this structure make electrons of each of the element in salt free to conduct electricity It's not correct to think of the electrical conductivity due to mobile electrons in this case. The solution conducts electrivity due to the movement of mobile ions. Electrical conductivity of solution of a substance depends on the Mobile charged particles. By the way, are all precipitates white in colour?
albertlee Posted November 3, 2004 Author Posted November 3, 2004 thx PrimaryGun... but two questions want to know.... I assume you mean the partial charge of H2O attract the ions from salt... But are'nt those partial charges attract on the partial charges of other H2O molecules?? I see no mean that those molecules break their attraction and attract the ions in salt... Secondly, when the ions are broken by H2O, the ions are not connecting to each other any more, but being attracted by the partial charge of H2O...., but if so, does'nt H2O makes the anion neutral??? I assume that only anion can carry heat, and electrcity, not cation... Any more help??
jdurg Posted November 3, 2004 Posted November 3, 2004 When you're thinking about the partial charge on water, what would you think has a stronger charge: an ion or a water molecule? The complete charge on the anions and cations provide a much stronger attraction for the water molecule as opposed to the weaker partial charge on the H2O molecules. Now, you might be thinking "How can there be a charge on the salt if it hasn't dissolved yet?" Well, the way a salt is composed is alternating positive and negative ions. At the edges, these ions are exposed to the water which has a slight charge on certain parts of it. What will happen is that the particles at the edges of the salt will see the water and want to move closer to the water molecules which can surround it in a more thermodynamically stable manner than the other ions can. Once one of them has moved away, it exposes more and more. Eventually the salt has totally dissolved. When the ion is fully solvated, it is not neutral. It still has a charge because it never has any electrons added to it or removed from it. They are still either positively charged or negatively charged, but they're stable due to the water molecules around it. Also, remember that electricity is not just the presence of electrons. Electricity is the movement of electrons from a negatively charged source to a positively charged source. A salt dissolved in water can carry electricity because the electrons will move from the negative source through the water via the ions, and to the positive side. (Damn. It sounded so clear in my head, but I can't get it out in words.)
Primarygun Posted November 4, 2004 Posted November 4, 2004 I am no idea on why water molecules are not being tore away. Maybe they do, but the rate is not as much as the decomposition of salt. By the way, do the motions of charged particles bring the electric shield move and thus electricity is generated? I haven't studied about the electricity and I have not learnt it. I just know charge particles generates electricity. Anyone helps?
albertlee Posted November 4, 2004 Author Posted November 4, 2004 At the edges, these ions are exposed to the water which has a slight charge on certain parts of it. What will happen is that the particles at the edges of the salt will see the water and want to move closer to the water molecules which can surround it in a more thermodynamically stable manner than the other ions can. Once one of them has moved away, it exposes more and more. Eventually the salt has totally dissolved. What do you mean by "move"??? water attract ions, or ions attract water?? Albert
Skye Posted November 4, 2004 Posted November 4, 2004 I believe he means that as the ions on the surface of the solid compound move away, into solution, the ions underneath are then exposed to undergo the same process.
Gilded Posted November 4, 2004 Posted November 4, 2004 "I believe he means that as the ions on the surface of the solid compound move away, into solution, the ions underneath are then exposed to undergo the same process." Heat makes this process faster because... ? The excited state of the ions causes them to move away more easily?
albertlee Posted November 4, 2004 Author Posted November 4, 2004 I believe he means that as the ions on the surface of the solid compound move[/i'] away, into solution, the ions underneath are then exposed to undergo the same process. Yes, so, what makes the ions move away?? I assume that there are two possiblityies 1) Water molecules attract ions 2) ions attract water molecules... But I think 1) makes more sense... Albert
Primarygun Posted November 5, 2004 Posted November 5, 2004 1,2 are true. It is relative. If ions do not attract water, how do water attract them? The attraction between the ions and molecules must be greater than the attraction bewteen ions and that of molecules, otherwise the small attraction cannot overcome the attractive forces and hence it is insoluble. Non-polar molecules are always slightly insoluble in water.
albertlee Posted November 5, 2004 Author Posted November 5, 2004 thx PrimaryGun.... By the way, What is the difference to the bond of partial charges compared with complete charges??? Albert
Primarygun Posted November 5, 2004 Posted November 5, 2004 It should be temporary and not stable. It sometimes becomes more strong and sometimes it becomes nil. It depends on the movement of the electrons. That's what I think.
albertlee Posted November 5, 2004 Author Posted November 5, 2004 Why none of metal can dissolve?? Albert
Primarygun Posted November 6, 2004 Posted November 6, 2004 Why none of metal can dissolve?? Solubility depends on the attractive forces between solute molecules and solvent molecules --A that of solvent molecules--B and that of solute molecule and solvent molecule--C. A must be larger than B and C, otherwise, the solute is non-soluble in that solvent. For metal, maybe it's because metals are composed of atoms, which is neutral and the situation is like a simple molecular structure put in water. Secondly,maybe the C is larger than A.
albertlee Posted November 6, 2004 Author Posted November 6, 2004 Primary gun... Metals are not made of molecules!!! By the way, the metals are not formed like a diamond.... It has both electrons as its anions and the atoms which loose all its outer shell electrons as its cations.... but it is interesting to think in this way, if metal is soluble to water... the electrons are being attracted by the negative partial charges of water molecules and the metal cations are being attracted by the positive patial chatges of water molecules but interesting thing is: Can the mere electrons be attracted by the partial chages in this way? Albert
Gilded Posted November 6, 2004 Posted November 6, 2004 "Metals are not made of molecules!!!" [nitpicking]Some metals occur as diatomic molecules[/nitpicking]
albertlee Posted November 7, 2004 Author Posted November 7, 2004 like what?? Glided By the way, any one can help to my previous post?? thx
jdurg Posted November 7, 2004 Posted November 7, 2004 I think that Beryllium exists as a polyatomic molecule. Mercury behaves that way as well, I believe.
albertlee Posted November 7, 2004 Author Posted November 7, 2004 Thx jdurg... By the way, can any one help on my second previous message?? that is, Can the mere electrons be attracted by the partial chages in this way? thx Albert
Primarygun Posted November 7, 2004 Posted November 7, 2004 I was implying something. Sorry to make you confused
albertlee Posted November 7, 2004 Author Posted November 7, 2004 implying what primarygun?? Any one to my previous message??
albertlee Posted November 7, 2004 Author Posted November 7, 2004 so, what is the answer to this?? Can the mere electrons be attracted by the partial chages in this way? in the situation that metals are being left in water... Albert
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