ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: mystikal on June 07, 2009, 10:47:44 pm
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if fats undergo hydrogenation does have a higher boiling point? Based on the fact that not only does it become more linear and can pack tightly close together as a result of it it should increase in boiling point
ive done 2 practice exams and they have said it lowers.
please i need help with this
and also what does it mean by incomplete combustion? can you give me an example.
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incomplete combustion is when there is limited oxygen or the oxygen gas is not in excess and carbon monoxide is produced rather than the carbon dioxide that u would find in complete combustion
Eg.
C4H12 +5O2 →4CO+6H2O
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Incomplete combusion is where you have CO and H2O as your products, instead of CO2 and H2O
So for example, if I had ethanol and it was not completely combusted, I would have the equation
2CH3CH2OH (aq) + 4O2 (g) --> 4CO (g) + 6H2O (g)
And I'm pretty sure you're right about the hydrogenated fat - because of its linear shape it would be able to form more dispersion forces with other fats which are very closely packed together. By that same token, single bonds require more energy to break than double bonds - hence a higher boiling temperature.
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incomplete combustion is when there is limited oxygen or the oxygen gas is not in excess and carbon monoxide is produced rather than the carbon dioxide that u would find in complete combustion
Eg.
C4H12 +5O2 →4CO+6H2O
Sorry, I didn't realised you had already answered the question...
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if fats undergo hydrogenation does have a higher boiling point? Based on the fact that not only does it become more linear and can pack tightly close together as a result of it it should increase in boiling point
ive done 2 practice exams and they have said it lowers.
please i need help with this
and also what does it mean by incomplete combustion? can you give me an example.
Saturated fats have a higher MELTING point than unsaturated fats, not necessarily boiling point.
Also incomplete combustion, C (carbon) may also form.
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if fats undergo hydrogenation does have a higher boiling point? Based on the fact that not only does it become more linear and can pack tightly close together as a result of it it should increase in boiling point
ive done 2 practice exams and they have said it lowers.
please i need help with this
and also what does it mean by incomplete combustion? can you give me an example.
Saturated fats have a higher MELTING point than unsaturated fats, not necessarily boiling point.
Also incomplete combustion, C (carbon) may also form.
oh on the exams they put down melting points and they said it was lower. this it what 2 exams said the chemology 2009 and tsfx 2009 (which was a bitch)
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Saturated fats have higher melting temp than unsaturated because they exist as solids at room temperature where as unsaturated fats exist as oils (liquids) at room temp.
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someone put some butter in the microwave and tell us the results
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oh on the exams they put down melting points and they said it was lower. this it what 2 exams said the chemology 2009 and tsfx 2009 (which was a bitch)
the TSFX one said "which statement incorrectly describes"
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Saturated fats have higher melting temp than unsaturated because they exist as solids at room temperature where as unsaturated fats exist as oils (liquids) at room temp.
Saturated fats tend to be straight chains, which means molecules can 'pack' closer. Unsaturated fats have kinks, and they don't fit together as well.
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oh on the exams they put down melting points and they said it was lower. this it what 2 exams said the chemology 2009 and tsfx 2009 (which was a bitch)
the TSFX one said "which statement incorrectly describes"
yea i just realised ==