Monobasic refers to the presence of one electron donor (base), in this case the sodium (Na) so the chemical formula for monobasic sodium phosphate is NaH2PO4. Monohydrate refers to how hydrated, or...
Na3PO4 is the chemical formula for sodium phosphate
2Na3PO4 + 3CaCl2 --> Ca3(PO4)2 + 6NaCl
2 Na3PO4 + 3 CaCl2 ---> Ca3(PO4)2 + 6NaCl
Sodium tripoly phosphate is used mainly as a food preservative and as an ingredient in cleaning products.