Question

For reaction

$CrO_2Cl_2 + NaOH \longrightarrow B + NaCl + H_2O$

$B + H^+ \longrightarrow C + H_2O$

Then number of terminal oxygen in C is ______

Answer 1

4

Answer 2

The compound $CrO_2Cl_2$ (chromyl chloride) reacts with $NaOH$ to form a chromate salt (B), which upon acidification gives chromic acid (C, $H_2CrO_4$). In chromic acid the chromium is tetrahedrally coordinated by four oxygen atoms, all of which are terminal.

Details:

1. $CrO_2Cl_2$ (with Cr in +6 oxidation state) reacts with $NaOH$ to yield a chromate salt.

2. Acidifying the chromate salt converts it to chromic acid $H_2CrO_4$.

3. In $H_2CrO_4$, the Cr atom is bonded to four oxygen atoms (all terminal).