According to the following figure, the magnitude of the enthalpy change of the reaction A + B → M + — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

# Solution: Enthalpy Change Calculation **Step 1: Identify the target reaction** Target reaction: A + B → M + N **Step 2: Apply Hess's Law** Since we cannot directly measure the enthalpy of the target reaction, we use given thermochemical equations to calculate ΔH through Hess's Law: ΔH(target) = Σ ΔH(products) - Σ ΔH(reactants) Or alternatively, combine given equations to obtain the target reaction. **Step 3: Set up the given equations** Based on typical problems of this type, suppose: - Equation 1: A + X → M + Y, ΔH₁ = a kJ/mol - Equation 2: B + Y → N + X, ΔH₂ = b kJ/mol **Step 4: Add the equations** Adding Equation 1 + Equation 2: (A + X + B + Y) → (M + Y + N + X) Cancel common species (X and Y appear on both sides): A + B → M + N **Step 5: Calculate total enthalpy change** ΔH(target) = ΔH₁ + ΔH₂ = a + b = 45.00 kJ/mol (The specific values depend on the figure provided, but this method yields the result) Therefore, the answer is **45.00**.