Problem: Given the following data2 O3 (g) → 3 O2 (g)            ΔH = -427 kJO2 (g) → 2O (g)                  ΔH = 495 kJNO (g) + O3 (g) → NO2 (g) + O2 (g)   ΔH = -199 kJCalculate ΔH for the reactionNO (g) + O (g) → NO2 (g) 

FREE Expert Solution
86% (153 ratings)
FREE Expert Solution

We’re being asked to determine the enthalpy change (ΔHrxn) for the chemical reaction:


NO (g) + O (g) → NO2 (g) 


We can use Hess’s Law to determine the enthalpy change of the overall reaction from the given reactions:


1. 2 O3 (g) → 3 O(g)                                                       ΔH1 = -427 kJ

2. O2 (g) → 2O (g)                                                            ΔH2 = 495 kJ 

3. NO (g) + O3 (g) → NO2 (g) + O2 (g)                              ΔH3 = -199 kJ


We now need to find a combination of reactions that when added up, gives us the overall reaction.


86% (153 ratings)
Problem Details

Given the following data

2 O3 (g) → 3 O(g)            ΔH = -427 kJ

O2 (g) → 2O (g)                  ΔH = 495 kJ

NO (g) + O3 (g) → NO2 (g) + O2 (g)   ΔH = -199 kJ

Calculate ΔH for the reaction

NO (g) + O (g) → NO2 (g) 

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