Final answer:
Without a balanced chemical equation that includes Na₂S₂O₃ and HCl, it is impossible to determine the molar relationship and calculate how many moles of HCl can form from 25.2 mol of Na₂S₂O₃.
Step-by-step explanation:
To determine how many mol of HCl can form from 25.2 mol of Na₂S₂O₃, we need a balanced chemical equation that includes both Na₂S₂O₃ and HCl as reactants or products. However, the provided information and examples do not include such an equation. Without the appropriate reaction, it is impossible to calculate the molar relationship between Na₂S₂O₃ and HCl and thus answer the question. If the student can provide the balanced equation, the stoichiometry can be used to solve for the amount of HCl that can be formed.