P₄O₁₀ react with cold water produce X (oxyacid) and P₄O₆ react with hot water produce Y(oxyacid) then atomicity of Y- atomicity of X =

The reaction details are as follows:

1. Reaction 1: P₄O₁₀ reacts with cold water:

   P₄O₁₀ + 6H₂O → 4H₃PO₃

   • The product X is H₃PO₃ (phosphorous acid).
   • Atomicity of X: 7 (counting all atoms in H₃PO₃).

2. Reaction 2: P₄O₆ reacts with hot water:

   P₄O₆ + 6H₂O → 3H₃PO₄ + PH₃

   • The product Y includes H₃PO₄ (phosphoric acid) and PH₃ (phosphine gas).
   • Atomicity of Y: 8 (counting all atoms in H₃PO₄).

Atomicity Difference (Y - X): 8 - 7 = 1

Concept Behind the Reactions:

Cold Water Reaction: P₄O₁₀ reacts with cold water to form H₃PO₃, which is a weaker oxyacid. 
Hot Water Reaction: P₄O₆ reacts with hot water to form a stronger oxyacid, H₃PO₄, along with PH₃. 
The difference in reactivity and products is due to the difference in oxidation states and the conditions (cold vs hot water) under which the reactions occur.