# Chemistry Hydrate Problem

1. Feb 1, 2005

### Raza

Hello, I need help to these two questions:

How would you write a chemical equation for this compound:
Barium Chloride Anhydrate
What I got so far is BaCl . ????

And what is the definition of Anhydrate?

Any help would be greatly appreciated!

2. Feb 1, 2005

### iansmith

Staff Emeritus
Should it be Anhydride rather than anhydate?

Anhydrede means that a compound is formed from one or more other compounds in a reaction resulting in removal of water.

3. Feb 1, 2005

### Gokul43201

Staff Emeritus
'Anhydrate' is the noun form of the adjective 'anhydrous' , which simply means 'without water'.

It is important to specify, in the case of certain hygroscopic (water absorbing) salts, whether you are talking about the hydrated salt, or the anhydrous salt (also known as the anhydrate). Copper sulfate, for instance hydrates itself with 5 molecules of water per molecule of copper sulfate. So, copper sulfate crystals will have the formula $CuSO_4 \cdot 5H_2O$ when left exposed to atmosphere (and look blue in color). When you heat the crystals sufficiently, you can vaporize and drive out the water leaving behind copper sulfate anhydrate $CuSO_4$, which is white in color.

Likewise with any other inorganic anhydrate. So, in the formula for the anhydrate, there is nothing after the "."

However, you seem to have made a mistake with the formula of barium chloride. What is the valency of Ba ? And Cl ?

4. Feb 1, 2005

### Raza

Oh yeah, my bad, its suppose to be BaCl2 I finally understand it now, Thank you very much guys!

Last edited: Feb 1, 2005