What is the color and structure of CrO3? [closed]








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What is the structure and color of $\ce{CrO3}$?


Also, is it possible to produce $\ce{CrO3}$ when dichromate is heated with sulphuric acid?




According to its [Wikipedia page](http://en.wikipedia.org/wiki/Chromium_trioxide):


**Color**


$\ce{CrO3}$ is a dark-purple solid under anhydrous conditions, that turns bright orange when wet.


**Production**


$\ce{CrO3}$ is generated, as you said, by the following reaction:


$$\ce{H2SO4 + Na2Cr2O7 -> 2 CrO3 + Na2SO4 + H2O}$$


**Structure**


Its monomeric structure is predicted to be pyramidal like so:


![chromium oxide monomer](https://i.stack.imgur.com/WdDEw.png)


Its crystalline structure is: 


![chromium oxide crystal](https://i.stack.imgur.com/gGmBv.png)


Each chromium center shares two oxygen centers with neighbors, but two oxygen atoms are not shared, giving the overall stoichiometric ratio of 1:3.


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