Re: ions (fwd)

[Delphi High School <pmason@wvec.k12.in.us>]

I forgot to add the last sentence. The water molecule is polar, having a 
partially positive end and a partially negative one. The water molecule 
can orient itself to 'attack" either the postive sodium ion or the 
negative chloride ion and remove this ion from the crystal. Chemists say 
"like dissolves like" meaning polar solvents are capable of dissolving 
polar covalent or ionic compounds. Compounds with polar bonds which are 
symmetrical are not soluble in water. 
Patti M

---------- Forwarded message ----------
Date: Sun, 20 Sep 1998 10:28:02 -0500 (EST)
From: Delphi High School <pmason@wvec.k12.in.us>
To: phys-l@mailer.uwf.edu
Cc: phys-L@atlantis.uwf.edu
Subject: Re: ions

On Sun, 20 Sep 1998, Ludwik Kowalski wrote:

> A grain of salt (pure crystal in dry air) is turned
> into very fine powder. Each powder particle is a
> neutral molecule NaCl. We put this powder into
> a glass of water and all molecules are ionized. Why?
>
> Ludwik Kowalski
TEchnically, there is no such thing as a molecule of NaCl, because 
molecules are compounds with covalent bonding. The bonding in NaCl is 
ionic and the NaCl exists as ion pairs in the crystalline structure. Upon 
dissolving in water, dissociation occurs, not ionization. The ions were 
already there. Molecules which are covalently bonded such as HCl ionize 
upon dissolving in water.
Sorry, but the chemist in me had to comment on this.
Patti Mason
Delphi High School
Delphi, IN