Question

When orthophosphoric acid is heated to 600$^{\circ}$C, the product formed is

• A. $PH_3$
• B. $P_2O_5$
• C. $H_3PO_3$
• D. $HPO_3$

Answer 1

Answer: (D)

$HPO_3$

Answer 2

When orthophosphoric acid $(H_3PO_4)$ is heated
and dehydration takes place. It form
metaphosphoric acid (HPO_3).
$H_3PO_4 \, \xrightarrow ? HPO_3 + H_2O$