Lemme guess, those kaplan orgo subject tests confused you too? They ask about melting point and the explanation is about boiling point, and vice versa lol. I guess they have some similarities but I would also like a breakdown!
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211183
HAHA yes!! I am doing them for review before my test tomorrow and am getting pretty discouraged because i feel like everything fell out of my brain. I think i'm just freaking out ha
So far I've extracted this info: (i think)
Melting Point is related the the packing of the molecules... less branching = higher MP
- also related to H-bonding abilities
Boiling Point is related to dipole moments and the IMForces..... so the larger the dipole the higher the BP
-also related to H-bonding..
RIGHT??
Ya, I though I had it. But after looking @kaplan book now I am so confused as well---it says that:
increase chains will increase b.p, m.p.,density
increase branching will decrease b.p., m.p., and density
BUT Destryer says
branching will increase m.p.
Can someone please clarify. I think I will go with destroyer. Orgoman knows what he is talking about.
increase chains will increase b.p, m.p.,density
increase branching will decrease b.p., m.p., and density
BUT Destryer says
branching will increase m.p.
Can someone please clarify. I think I will go with destroyer. Orgoman knows what he is talking about.
Less branching = easier to pack together/tighter = higher mp
I think Kaplan is right on this one!
Which properties apply to both mp and bp? I think kaplan mentions polarity..?
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i think BP is related to polarity..... because in a liquid... if you have polarity, the molecules are likely to stay together through IMForces...
In solids, i believe ability of packing is more important...
Both want H-bonding
Both want less branching...
But, in BP, if branching gives it a dipole, i think it takes precedence.
Am I answering my own Q's??? Someone confirm. My mind is everywehre because I am confused I got stupid in one night since my test is tomorrow... I knew I shouldn't have tried to review today!
In solids, i believe ability of packing is more important...
Both want H-bonding
Both want less branching...
But, in BP, if branching gives it a dipole, i think it takes precedence.
Am I answering my own Q's??? Someone confirm. My mind is everywehre because I am confused I got stupid in one night since my test is tomorrow... I knew I shouldn't have tried to review today!
melting point:
symmetry means everything, i.e. trans alkene, because of the symmetrical shape, it can pack tighter, lead to high m.p. cause you need to have more energy to break the intermolecular force.
boiling point:
look for polarity, i.e. cis alkene is more polar than trans (I wish I could draw it out, it's kinda hard to explain...) thus it has higher b.p.
symmetry means everything, i.e. trans alkene, because of the symmetrical shape, it can pack tighter, lead to high m.p. cause you need to have more energy to break the intermolecular force.
boiling point:
look for polarity, i.e. cis alkene is more polar than trans (I wish I could draw it out, it's kinda hard to explain...) thus it has higher b.p.
In Kaplan it also related polarity to melting point (which I think was the initial point of confusion).
