Compute the total enthalpy change by using the Hess Law

Question

Use the Hess law to calculate the total enthalpy

2H₂O ------> 2H₂ + O₂ +572 KJ/mol

2HF  ------> H₂ + F₂ + 542 KJ/mol

Answer 1

You don't have the target equation listed. General rule: However you combine the equations (multiplying by a constant and adding), you do the same thing in combining the enthalpies.