7. Sodium tripolyphosphate (STPP) is made by reacting saturated soda ash solution and orthophosphoric acid. To form one mole of monosodium to two moles of disodium phosphate ratio of Na2O/P2O5 must be
A. 1.67
B. 17.6
C. 0.167
D. 16.7
7. Sodium tripolyphosphate (STPP) is made by reacting saturated soda ash solution and orthophosphoric acid. To form one mole of monosodium to two moles of disodium phosphate ratio of Na2O/P2O5 must be
A. 1.67
B. 17.6
C. 0.167
D. 16.7