Answer:
Step-by-step explanation:
Phosphoric acid H₃PO₄ is produced from reaction of water and tetraphosphorus decoxide P₄O₁₀ as follows
P₄O₁₀ + 6 H₂O = 4 H₃PO₄
In this reaction 6 molecules of H₂O and one molecule of phosphorus compound P₄O₁₀ is needed to produce phosphoric acid , ie the conversion factor of water to acid is 6 / 1
This ratio is called mole ratio of water to H₃PO₄.
So the required ratio is 6 : 1 .