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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: zibb3r on April 03, 2011, 11:51:01 am

Title: How to tell.....?
Post by: zibb3r on April 03, 2011, 11:51:01 am

I am giving 2 substances.  1 is propane and 1 is propan-1-ol, but I don't know which is which.  What can I do to find out???

I thought maybe add water to both and then propanol would react but propane wouldn't because of polarity???

THanks :smitten:

Title: Re: How to tell.....?
Post by: pi on April 03, 2011, 11:55:17 am

I think your idea would work, because as propane is fully non-polar, there would be separation between propane and water (two distinct layers), whilst propanol would mix with the water (is polar).

I'm interested to know more too

Title: Re: How to tell.....?
Post by: Russ on April 03, 2011, 11:58:14 am

Add anything that reacts with a hydroxyl group (eg alcohol reduction) and check for the reaction process/product

Title: Re: How to tell.....?
Post by: nacho on April 03, 2011, 01:07:09 pm

Quote from: Russ on April 03, 2011, 11:58:14 am

Add anything that reacts with a hydroxyl group (eg alcohol reduction) and check for the reaction process/product

isn't it alcohol oxidation?

Also, at room temperature, propane is a gas and propanol is a liquid :D

Title: Re: How to tell.....?
Post by: Mao on April 03, 2011, 02:30:28 pm

@Russ, @nacho, as chemists, we try to do the simplest experiment, because they are the easiest and most reliable (less steps = less chance of everything going wrong).

Dissolution in water (@pi, @zibb3r) is a very easy test that will distinguish the two. (There's no reaction, just dissolution. We can distinguish two substances without a reaction.)

There is even an easier way, propanol has a much higher boiling point than propane. (Propane is a gas at room temperature, propanol is a liquid.) You will be able to tell just by looking at the two substances at room temperature.

Moderator action: removed real name, sorry for the inconvenience

Title: Re: How to tell.....?
Post by: Russ on April 03, 2011, 02:38:03 pm

Quote from: Mao on April 03, 2011, 02:30:28 pm

@Russ, @nacho, as chemists, we try to do the simplest experiment,

As a bucket chemist (biologist) I just throw everything together and make up a conclusion :)