quatumrulesoverall Posted September 9, 2006 Report Share Posted September 9, 2006 I have another quetion for you all, alright when solute is added to the solution the boiling point and freezing point of the solution will change, right? But if the boiling point and melting point of the solute is so much greater than the pure solvent, what is the state of solute molecules when boiling point and freezing point of the solvent is reached? :eek_big: :shrug: :shrug: Quote Link to comment Share on other sites More sharing options...
Mercedes Benzene Posted September 9, 2006 Report Share Posted September 9, 2006 But if the boiling point and melting point of the solute is so much greater than the pure solvent, what is the state of solute molecules when boiling point and freezing point of the solvent is reached? Well, if you bring the solvent up to a boil, it will eventually all evaporate, leaving the solid solute behind. If you freeze the solvent, then the particles of the solute will stay solid particles...Remember, solids are technically in the "frozen state of matter". We just don't think of it this was because when we think of frozen, we think of ice. Hope this helps!:eek_big: Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted September 9, 2006 Report Share Posted September 9, 2006 The freezing and boiling temp of solvents can be altered by the addition of solutes. Anti-freeze or ethylene glycol that you put in your car is one such example. When water boils the bubbles are mainly oxygen, which was previously dissolved in the water. And from MB's example solid dissolved particles will leave behind a precipitate, such as salt, when boiled. So you see that the solute will revert back to its state prior to been disolved, this will not always be the case if it is near a phase change point of the solute, then you could get some funky things happening! Quote Link to comment Share on other sites More sharing options...
Vending Posted September 13, 2006 Report Share Posted September 13, 2006 The freezing and boiling temp of solvents can be altered by the addition of solutes. Anti-freeze or ethylene glycol that you put in your car is one such example. Even more, the addition of solutes to a solution ALWAYS raises the boiling temp and lowers the metling point. When water boils the bubbles are mainly oxygen, which was previously dissolved in the water. I don't think so. When water boils, the bubbles are mainly H2O in the gaseous phase. The boiling of water is the physical transition of H2O from liquid to gas. So the bubbles are mainly H2O. By the time that water is boiling most of the gaseous impurities will have already left solution, since the solubility of GASES decreases with increasing temperature (this is of course the opposite trend observed in the case of solid impurites). Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted September 13, 2006 Report Share Posted September 13, 2006 hence the bubbles.. notice the water temp doesnt have to be 100 degrees celcius to get bubbles. I dont know how you would check, but I am pretty sure there would be more oxygen.. Quote Link to comment Share on other sites More sharing options...
quatumrulesoverall Posted September 13, 2006 Author Report Share Posted September 13, 2006 Alright, I would like to reveal the answer, so that we can check and discuss more. Yes, what you all say is true, however none of you succeeded in answering the question. What is the state of benzoic acid molecules ? You may try to think again (Hint: something ends with -mer ) Quote Link to comment Share on other sites More sharing options...
Mercedes Benzene Posted September 13, 2006 Report Share Posted September 13, 2006 Yes, what you all say is true, however none of you succeeded in answering the question. What is the state of benzoic acid molecules ? You may try to think again (Hint: something ends with -mer ) You never asked that......and its a solid at room temperature. Quote Link to comment Share on other sites More sharing options...
quatumrulesoverall Posted September 13, 2006 Author Report Share Posted September 13, 2006 You never asked that......and its a solid at room temperature.I did ask man, by the way, the substance is in solid state, I agree, however, the molecules are not .... look at the hint( -mer)anyway, your avatar looks so cool, it is your own image. Quote Link to comment Share on other sites More sharing options...
Mercedes Benzene Posted September 13, 2006 Report Share Posted September 13, 2006 I did ask man, by the way, the substance is in solid state, I agree, however, the molecules are not .... look at the hint( -mer)anyway, your avatar looks so cool, it is your own image. Mercury?;) And molecules are never really "solid" unless you reach absolute zero... in which case the world might end. :hihi: I'm still not sure what you're getting at... And yes, my avatar is my own picture. I put it up after I played around some... only to find out my "chemical" avatar was deleted by my computer. I hope to get it back shortly. :) Quote Link to comment Share on other sites More sharing options...
quatumrulesoverall Posted September 14, 2006 Author Report Share Posted September 14, 2006 Just leave it there, this one is better, anyway it is a monomer and trimer, as you can calculate the van hoff factor. Quote Link to comment Share on other sites More sharing options...
quatumrulesoverall Posted September 14, 2006 Author Report Share Posted September 14, 2006 Doh! I dont know that your nick is mercedes benzene, that's y you so interested.... lol, just leave your avatar, it looks cool.. Quote Link to comment Share on other sites More sharing options...
Mercedes Benzene Posted September 14, 2006 Report Share Posted September 14, 2006 Just leave it there, this one is better, anyway it is a monomer and trimer, as you can calculate the van hoff factor. Oh... I didn't think of that. haha. Doh! I dont know that your nick is mercedes benzene, that's y you so interested.... lol, just leave your avatar, it looks cool.. Thanks. It's the popped collar isn't it? I thought so. hahaha. :phones: Quote Link to comment Share on other sites More sharing options...
HydrogenBond Posted September 15, 2006 Report Share Posted September 15, 2006 When we add two solvents together some interesting things can happen. For example if one boils kerosine with water, the BP of kerosine will go way down and evaporate off with the water. The two don't mix well in the liquid phase but leave together in the vapor phase. This is called stream distillation. Ethanol and water will mix together but will freeze, at least partially, at separate temperatures. Apple jack in the winter is made this way with the alcohol last to freeze. If one boils water and ethanol, the BP is not linear to concentration but follows a curve. At 190proof, one hits an azeotrope, where water suddenly boils off easier than the much lower BP alcohol. The alcohol BP will suddenly increase. This why 190proof is usually the strongest consumable alcohol, since any further boiling will dilute this by adding more water than alcohol. Quote Link to comment Share on other sites More sharing options...
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