Chemistry Question...

• Darkness_hacker99

  26 Sep 06, 17:10

  My Prelim got this question on how to differenciate between dilute propanoic acid and propanol.
  
  1. Can it be differenciated by testing their electrical conductivity???
  
  2. Can it be differenciated by reacting them with sodium chloride???
  
  Thanks in advance..
• poon cho tang

  26 Sep 06, 17:13

  Originally posted by Darkness_hacker99:

  My Prelim got this question on how to differenciate between dilute propanoic acid and propanol.
  
  1. Can it be differenciated by testing their electrical conductivity???
  
  2. Can it be differenciated by reacting them with sodium chloride???
  
  Thanks in advance..

  1. the dilute acid has H+ ions so can conduct electricity more than propanol
  
  2. dun tink both canr eact with salt
  
  well...haben touch chemistry for 14 yrs liow
• MohamedF

  26 Sep 06, 17:17

  Wait a minute... shouldn't proponal + electricity = BOOOOM?
• poon cho tang

  26 Sep 06, 17:18

  conducting electricity is not the same as running lightning through it
• missqi

  26 Sep 06, 17:20

  propanol cannot react with NaCl lah...
  (i think)
  very long nv touch chem liao...
  since o lvls last yr.
  
• Darkness_hacker99

  26 Sep 06, 17:28

  From what I know, dilute acids can conduct electricity well because of their adundance of free hydrogen cations and anions when the acid molecules ionize in water...
  
  
• kaister

  26 Sep 06, 17:50

  Originally posted by Darkness_hacker99:

  My Prelim got this question on how to differenciate between dilute propanoic acid and propanol.
  
  1. Can it be differenciated by testing their electrical conductivity???
  
  2. Can it be differenciated by reacting them with sodium chloride???
  
  Thanks in advance..

  My chemistry mostly return to my teachers liao but I think I might know the answer.
  
  It is easier to use carbonates (eg, Na2CO3) to test for acidsas you can see the bubbling reaction from CO2 given out. Alcohol does not react with carbonates.
  
  Not sure about electrical conductivity but with sodium chloride, you only get water from the reaction... good luck trying to find water in the solution...
• kenshin_himura

  26 Sep 06, 17:59

  or add potassium dicromate bah... alcohol will be oxidised to carboxylic acids... dun tink carboxylic acids can be further oxidised
  
  so the one containing propanol will decolurise K2Cr2O7 but not the one containing propanoic acid
• stellazio

  26 Sep 06, 18:02

  until now i still can't calculate mol and all those stuff..
• Darkness_hacker99

  26 Sep 06, 18:02

  Originally posted by kaister:
  
  
  My chemistry mostly return to my teachers liao but I think I might know the answer.
  
  It is easier to use carbonates (eg, Na2CO3) to test for [b]acidsas you can see the bubbling reaction from CO2 given out. Alcohol does not react with carbonates.
  
  Not sure about electrical conductivity but with sodium chloride, you only get water from the reaction... good luck trying to find water in the solution... [/b]

  The reaction you've name is which one??
  
  Propanol with sodium chloride = X + water
  
  OR
  
  Propanoic acid with sodium chloride = X + water?
  
  Which one?
• kaister

  26 Sep 06, 18:10

  sorry... my bad... there's no reaction with sodium chloride. It's an inert salt. Told you my chemistry return to my teachers liao.
  
  But anyway, trust me on the test with carbonates with propanoic acid. The bubbling reaction sure cannot miss one
• Darkness_hacker99

  26 Sep 06, 18:14

  Originally posted by kaister:

  sorry... my bad... there's no reaction with sodium chloride. It's an inert salt. Told you my chemistry return to my teachers liao.
  
  But anyway, trust me on the test with carbonates with propanoic acid. The bubbling reaction sure cannot miss one

  Okie.
• Darkness_hacker99

  26 Sep 06, 18:17

  Originally posted by kenshin_himura:

  or add potassium dicromate bah... alcohol will be oxidised to carboxylic acids... dun tink carboxylic acids can be further oxidised
  
  so the one containing propanol will decolurise K2Cr2O7 but not the one containing propanoic acid

  Okie, thx..
• missqi

  26 Sep 06, 18:17

  Originally posted by stellazio:

  until now i still can't calculate mol and all those stuff..

  noob.
  no wonder u failed.
  
• Darkness_hacker99

  26 Sep 06, 18:26

  Originally posted by missqi:

  noob.
  no wonder u failed.
  

  You can't say him noob.
  
  Albert Einstein once said this :
  
  It's not that I'm so smart; it's just that I stay with problems longer.
• the wise one

  6 Oct 06, 16:00

  Originally posted by Darkness_hacker99:

  You can't say him noob.
  
  Albert Einstein once said this :
  
  It's not that I'm so smart; it's just that I stay with problems longer.

  Looks like ive got to say this too..
• hisoka

  6 Oct 06, 16:07

  taste test
  
  or else i think can try rate of evaporation. or can use nmr
• ctstalin

  6 Oct 06, 16:35

  Originally posted by hisoka:

  taste test
  
  or else i think can try rate of evaporation. or can use nmr

  hisoka long time nvr do chem liao ar?
  we're not allowed to use nmr to differentiate organic compounds, if not i won't be having so much problem with organic chem liao
• RETARDED_MORON

  6 Oct 06, 19:52

  Originally posted by Darkness_hacker99:

  My Prelim got this question on how to differenciate between dilute propanoic acid and propanol.
  
  1. Can it be differenciated by testing their electrical conductivity???
  
  2. Can it be differenciated by reacting them with sodium chloride???
  
  Thanks in advance..

  Add Sodium Carbonate (a weak base) and test for Carbon Dioxide. The acid will release Carbon Dioxide, while the alcohol will not due to its low acidity.
• PointBlue

  6 Oct 06, 19:54

  Can also add 2,4-dinitrophenylhydrazine to test for the alcohol, to form a orange hydrazone ppt.
• ^tamago^

  6 Oct 06, 19:55

  Originally posted by Darkness_hacker99:

  My Prelim got this question on how to differenciate between dilute propanoic acid and propanol.
  
  1. Can it be differenciated by testing their electrical conductivity???
  
  2. Can it be differenciated by reacting them with sodium chloride???
  
  Thanks in advance..

  litmus?
  
  propanol shld be alkaline......
• hisoka

  6 Oct 06, 20:12

  Originally posted by ctstalin:

  hisoka long time nvr do chem liao ar?
  we're not allowed to use nmr to differentiate organic compounds, if not i won't be having so much problem with organic chem liao

  why not allowed??
  
  only inorganic can arh??
  
  i never do chem in jc so dunno mah
  
  hmmz IR lor then
• d3sT1nY

  6 Oct 06, 20:36

  RJ student has already said his piece.. Why are you all still giving answers..
  
  Anyway.. Cannot use 2,4-DNPH.. Unless it's propan-2-ol.. Or butan-2-ol.. Propan-1-ol cannot be distinguished by 2,4-DNPH.. Go figure..
  
  Also cannot use litmus paper.. Must use organic reactions to distinguish.. Unless is testing for ammonia gas.. Then can use litmus paper.. Same goes for NMR.. No physical method..
  
  
• the.owl

  7 Oct 06, 00:09

  Originally posted by Darkness_hacker99:

  My Prelim got this question on how to differenciate between dilute propanoic acid and propanol.
  
  1. Can it be differenciated by testing their electrical conductivity???
  
  2. Can it be differenciated by reacting them with sodium chloride???
  
  Thanks in advance..

  use litmus paper la.