✔ 最佳答案
Consider the carbon dioxide gas formed in the reaction :
Pressure, P = 734/760 atm
Volume, V = 0.023 m³ = 23 L
Gas constant, R = 0.08206 L atm / (mol K)
Temperature, T = (273 + 250) K = 523 K
Gas law : PV = nRT
No. of moles of CO₂ produced = PV/RT = (734/760) × 23 / (0.08206 × 523) mol = 0.518 mol
Ca(HCO₃)₂ would decompose to give CaCO₃, H₂O and CO₂. However, CaCO₃ would further decompose to give CaO and CO₂ in such a high temperature of 250°C. Hence, the equation for the reaction is :
Ca(HCO₃)₂ → CaO + H₂O + 2CO₂
Mole ratio Ca(HCO₃)₂ : CO₂ = 1 : 2
No. of moles of Ca(HCO₃)₂ used = (0.518 mol) × (1/2) = 0.259 mol
Molar mass of Ca(HCO₃)₂ = (40.01 + 1.0×2 + 12.0×2 + 16.0×6) g/mol = 162.1 g/mol
Mass of Ca(HCO₃)₂ used = (162.1 g/mol) × (0.259 mol) = 42.0 g