Water molecule in chemical formulas of inorganic compounds

[gracy]

In chemical formulas of various inorganic compounds there are molecules of water .I wanted to know is it important to remember the number of moles of water in chemical formulas of inorganic compounds.

 

[Borek]

Depends. Some compounds - like copper sulfate - are so often used used as hydrates, that remembering their formula is a must (pentahydrate for copper sulfate). Other compounds can exist in many forms (calcium chloride can be prepared as dihydrate, tetrahydrate and hexahydrate) and remembering them all is not necessary.

 

[DrDu]

What is certainly important is to remember that there may be water around when calculating the molar mass.

 

[Borek]

Pretty good point.

 

[gracy]

What is certainly important is to remember that there may be water around when calculating the molar mass.

You mean to say that we include number of moles of water while calculating molar mass of compounds,right?

 

[Borek]

Yes. Say, you need 1 mole of copper and you have copper sulfate pentahydrate. What mass of the solid do you need?