[twinkling]

Hello there!

I'll apologise in advance for the complete elementary questions I will ask.  I have tried my best with the resources I have at hand.

Any help would be greatly appreciated!

I know that sulphur can form chlorides such as SCl₂ and S₂Cl₂.  But can they react with water?  And what products would be made?  I think that they would be acids.

Also, I know the tetrahedral shape of phosphorus pentachloride, but in its solid form it's ionic.

Possibly, [P]5+ and 5[Cl]-?

I'm not sure how they would be arranged structurally.

I'm sorry that there are two seperate questions.

Thank you.

[jdurg]

Well, a few of the 3rd period elements do react with water.  Sodium definitely does.  Magnesium reacts with gaseous water, and chlorine reacts mildly with water to form HCl and HOCl.  I don't know of any reactions between sulfur or phosphorus and water.  (In fact, white phosphorus is actually stored in water).  Whether or not they form acids also depends on where they are on the periodic table.  The elements to the left of the table will generally form bases with water, and those on the right will generally form acids.  (Sodium reacts with water to produce NaOH which is a base, and Mg reacts with steam to form Mg(OH)₂ which is a base.  As I had mentioned earlier, chlorine produces an acid when reacting with water).  Aluminum forms a protective layer of aluminum oxide on its surface which prevents its reaction with water, but I do know that aluminum hydroxide is somewhat amphoteric.  (That is, it sometimes acts as a base and sometimes acts as an acid).  The oxides of the elements are generally what determines whether or not its a base or acid in water.  Sodium, Magnesium, and very slightly Aluminum oxides will form bases, while Sulfur, chlorine, and phosphorus oxides form acids.  I really have no clue about silicon.  I'm fairly certain that all silicon oxides are completely non-reactive with water.  If they were, sand would not exist!  (Silicon oxides are generally pretty inert).

As for the structure, I'll have to get back to you later on that one.  

[twinkling]

Of course!  Sand doesn't react with water  

Thanks jdurg!

[puru]

PCl5 does not  have a tetrahedral shape.It is sp3d hybridized.Hense accordingly Trigonal Bipyramid Shape.