The Student Room Group

MgCl and SiCl

Describe the differences in behaviour when magnesium chloride and silicon (IV) chloride are added sperately to cold water.
You should include:
The pH of any resulting solution
relevant chemical equations
experimental observations
the name of the process taking place

I can't find any places to revise this, is it something to do with charge density?
Reply 1
Avatar for shengoc
shengoc
12
Original post by Eloades11
Describe the differences in behaviour when magnesium chloride and silicon (IV) chloride are added sperately to cold water.
You should include:
The pH of any resulting solution
relevant chemical equations
experimental observations
the name of the process taking place

I can't find any places to revise this, is it something to do with charge density?


http://www.chemguide.co.uk/inorganic/period3/chlorides.html
In both the cases the cations undergo hydrolysis to give H+ ions and hence pH decreases. The resultant pH depends on the amount of chloride and water used. It is advisable to use very cold water in case of SiCl4. Add the chloride to very cold water slowly.
Reply 3
Avatar for Eloades11
Eloades11
OP
17
Original post by shengoc


Thanks, but the guide didn't really explain it well for aluminium chloride or silicon chloride. Is it covalently bonded? I don't understand
Reply 4
Avatar for shengoc
shengoc
12
Original post by Eloades11
Thanks, but the guide didn't really explain it well for aluminium chloride or silicon chloride. Is it covalently bonded? I don't understand


http://revision-notes.co.uk/Detailed/1076.html

bonding can be a bit complicated to understand sometimes, but as long as you are aware of electronegativity difference resulting in polarisation of charge density => slight ionic character amongst covalent molecules and in contrast when you have small cations, large anions => this tends to give you polarisation of charge clouds in ionic molecule.

the idea is that covalency can arise in ionic molecules, and vice versa too. a lot of bonding is simply described in terms of the predominant type.
Reply 5
Avatar for Eloades11
Eloades11
OP
17
Original post by shengoc
http://revision-notes.co.uk/Detailed/1076.html

bonding can be a bit complicated to understand sometimes, but as long as you are aware of electronegativity difference resulting in polarisation of charge density => slight ionic character amongst covalent molecules and in contrast when you have small cations, large anions => this tends to give you polarisation of charge clouds in ionic molecule.

the idea is that covalency can arise in ionic molecules, and vice versa too. a lot of bonding is simply described in terms of the predominant type.


Thanks a lot :smile:
Original post by Eloades11
Thanks, but the guide didn't really explain it well for aluminium chloride or silicon chloride. Is it covalently bonded? I don't understand


SiCl bond is covalent whereas MgCl bond is more ionic. The reason is polarizability difference

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you