Question

\(H_3 PO_4 \,\, ^{\underrightarrow{1}} H_4 P_2 O_7 \,\, ^{\underrightarrow{1}}  HPO_3\)  Indicate the temperatures 1and 2?

(a) 1.300°C    2.1000°C

(b) 1.250°C    2.900°C

(c) 1.250°C     2.500°C

(d) 1.100°C     2.1000°C

This question was addressed to me in final exam.

Question is from Inorganic Chemical in chapter Inorganic Chemical Industries of Chemical Technology

Answer 1

Right answer is (b) 1.250°C    2.900°C

Easy explanation: Ortho phosphoric acid on heating to 250°C  gives pyro phosphoric acid, which on further heating to 900°C produces meta phosphoric acid.