Question

Sure! Here's a question:Calculate the enthalpy change for the following chemical reaction: 2H2 (g) + O2 (g) → 2H2O (l) Given the following enthalpy changes: 2H2 (g) + O2 (g) → 2H2O (g) ΔH = -483.6 kJ/mol 2H2O (g) → 2H2O (l) ΔH = -40.7 kJ/mol

Answer 1

To calculate the enthalpy change for the given reaction, we can use Hess's Law, which states that the total enthalpy change for a reaction is the sum of the enthalpy changes for each step in the reaction.We are given two reactions:1  2H2  g  + O2  g   2H2O  g  H1 = -483.6 kJ/mol2  2H2O  g   2H2O  l  H2 = -40.7 kJ/molThe overall reaction we want to find the enthalpy change for is:2H2  g  + O2  g   2H2O  l To find the enthalpy change for this reaction, we can add the enthalpy changes for the two given reactions:H_total = H1 + H2H_total =  -483.6 kJ/mol  +  -40.7 kJ/mol H_total = -524.3 kJ/molSo, the enthalpy change for the reaction 2H2  g  + O2  g   2H2O  l  is -524.3 kJ/mol.