Question

For $Cr{O}_3$, the incorrect statement is:

• A. it is called chromic acid
• B. it is colourless due to $3d^{10}$ configuration
• C. it is bright orange solid and colour arises due to charge transfer
• D. it is toxic and corrosive

Answer 1

The correct option is B it is colourless due to $3d^{10}$ configuration

Chromium trioxide $Cr{O}_3$ is the acidic anhydride of chromic acid. This is a dark-purple solid under anhydrous conditions, bright orange when wet and which dissolves in water concomitant with hydrolysis.
Chromium trioxide is highly toxic, corrosive, and carcinogenic.