Q. Sodium pyrophosphate is represented by which of the following formula?
ManipalManipal 2007The s-Block Elements
Solution:
Sodium pyrophosphate is represented by $Na _{4} P _{2} O _{7}$. It is sodium salt of pyrophosphoric acid $\left( H _{4} P _{2} O _{7}\right)$, which may be considered to be made up by two molecules of ortho phosphoric acid $\left( H _{3} PO _{4}\right)$, eleminating one molecule of $H _{2} O$.
$2H_3PO_4 \xrightarrow{-H_2O} \underset{\text{Pyrophosphoric acid}}{H_4P_2O_7}$
