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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: mmetecaliskan on October 09, 2007, 05:50:45 AM

Title: ebonite
Post by: mmetecaliskan on October 09, 2007, 05:50:45 AM

it seems to be easy but i couldnt find the answer of this question.I hope one of you will help me to find the answer .
now my question is :

why  do ebonite attract pepper but not salt

Title: Re: ebonite
Post by: P on October 09, 2007, 06:59:52 AM

This is just a guess based on logic  -  please correct me if I'm wrong.

Ebonite is a plastic right? An organic polymer!

In chemistry - 'like' dissolves 'like'   - also polymers get charged and attract.

Pepper  -  being organic  -  is attracted electrostatically to the organic polymer ebonite. Salt - being ionic - is not.

please correct me if I'm wrong.    :)

Title: Re: ebonite
Post by: Borek on October 09, 2007, 08:49:37 AM

Quote from: P on October 09, 2007, 06:59:52 AM

please correct me if I'm wrong.    :)

You are wrong. Feel corrected ;)

Title: Re: ebonite
Post by: P on October 09, 2007, 10:14:59 AM

Quote from: Borek on October 09, 2007, 08:49:37 AM

Quote from: P on October 09, 2007, 06:59:52 AM

please correct me if I'm wrong.    :)

You are wrong. Feel corrected ;)

oh well -  said it was just a guess.

 :'(  boo hoo.... :'(    -  ok - I've tried feeling corrected - but I just feel wrong!  ;D

What is the real reason then??

Title: Re: ebonite
Post by: Borek on October 09, 2007, 11:27:54 AM

Well, I don't have to be sure about the real answer, to recognize wrong one ;)

Title: Re: ebonite
Post by: P on October 10, 2007, 04:08:38 AM

pretty sure it should be something to do with electrostatic charge though!

Title: Re: ebonite
Post by: Mitch on October 10, 2007, 01:26:02 PM

It is definitely an electrostatic effect.

Title: Re: ebonite
Post by: Maz on October 13, 2007, 11:26:31 PM

Electrostatics is correct, but way too broad. 

But the problem is stated incorrectly.  "Raw" ebonite wouldn't attract pepper, it would have to be rubbed with a wool (or some other high-friction) cloth first. 

For instance, most plastic spoons would work just as well if rubbed correctly.

So, I think it's all but obvious now. 

Well, except for maybe why pepper gets an induced charge seperation easier then salt.    As in pepper requires a weaker external electric field to get the charge sep. then salt.

But I think you chemists should jump on that one in a hurry.  ;)

Title: Re: ebonite
Post by: Mitch on October 14, 2007, 03:33:36 PM

Yes, stereo-electronic effect. :P