Chemistry - Salt Analysis Question with Solution | TestHub

Lead chromate is yellow in color due to their absorption and reflection of specific wavelengths of light.

${\mathrm{PbCrO}}_4 + \mathrm{NaOH} (\mathrm{hot} \mathrm{excess}) \to \left[\mathrm{Pb}\right(\mathrm{OH}{)}_4]{ }^{-2} + {\mathrm{Na}}_2{\mathrm{CrO}}_4$

The complex formed is ${\left[\mathrm{Pb}{\left(\mathrm{OH}\right)}_4\right]}^{2-}$

which has coordination number $=4$ and complex is dianionic due to presence of $\left(-2\right)$ charge.

coordination number, the number of atoms, ions, or molecules that a central atom or ion holds as its nearest neighbours in a complex or coordination compound or in a crystal.