Balanced Equation Questions.?

Question

I'm trying to understand writing equations for reactions. If your answer this question for me, please try your best to explain why and how as well.

a) hydrolysis of PCl5

b) dehydration of orthophosphoric acid to form pyrophosphoric acid

c) reaction of P4O10 with water.

any help would be greatly appreciated, thanks.

Answer 1

a) hydrolysis of PCl5

since I am not sure of the amount of hydrolysis PCl5 under goes, I went to :

http://en.wikipedia.org/wiki/PCl5

"In its most characteristic reaction, PCl5 react upon contact with water to release hydrogen chloride and give phosphorus oxides. The first hydrolysis product is phosphorus oxychloride:

PCl5 + H2O → POCl3 + 2 HCl

In hot water, hydrolysis proceeds completely to ortho-phosphoric acid:

PCl5 + 4 H2O → H3PO4 + 5 HCl "

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b) dehydration of orthophosphoric acid ,(2 H3PO4 -->),to form pyrophosphoric acid(-->H4P2O7)

the difference between 2 H3PO4 's & 1 H4P2O7  is only 1 H2O, so your answer is:

2H3PO4 -->  H4P2O7 + H2O

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c) reaction of P4O10 with water.

this re-makes by  H3PO4, re-hydration

1 P4O10  &  6 H2O  Ã¢Â†Â’ 4 H3PO4