Sketch the phase diagram for Na2O-Nb2O5 using the following information and label all regions on the diagram. Indicate the peritectic line and what exist in that line.

Four compounds are stabilized from Na2O and Nb2O5 mixture.

Na3NbO4 melts congruently at 992 C.

NaNbO3 melts congruently at 1412 C.

NaNbO3 undergoes phase transition at 368 ( to phase) and 640 C ( to g phase)

Na2Nb8O21 melts incongruently at 1265 C to (Na2Nb20O51 + liquid)

Na2Nb20O51 melts incongruently at 1290 C to (Nb2O5 + liquid)

Na2O melts at 1200 C

Nb2O5 melts at 1485 C

Eutectics at:

- 10% Nb2O5 at 830 C

- 31% Nb2O5 at 975 C

- 68% Nb2O5 at 1220 C

(Hint: Na2O + Nb2O5 -> 2NaNbO3.)