Q1: Heating of orthophosphoric acid to 250°C produces

ANS:B - pyrophosphoric acid

Pyrophosphoric acid, with the chemical formula H4P2O7, is an acid formed from the dehydration and condensation of two molecules of orthophosphoric acid (H3PO4). This condensation reaction occurs when orthophosphoric acid is heated to around 250°C. Pyrophosphoric acid is characterized by the presence of two phosphate groups linked by an oxygen atom. Its structure can be visualized as two orthophosphoric acid molecules joined together with the loss of a water molecule. The resulting compound has unique chemical properties compared to orthophosphoric acid. Pyrophosphoric acid is often used in various industrial processes, including the production of detergents, water treatment, and as a precursor in the synthesis of other phosphorus-containing compounds. It plays a crucial role in biochemical processes within living organisms, where it is involved in energy transfer reactions and as a component of nucleic acids and coenzymes.