Question

What is the enthalpy change for the isomerization of 2-butene to 1-butene at constant pressure, given that the standard enthalpy of formation of 2-butene is -118.0 kJ/mol and the standard enthalpy of formation of 1-butene is -133.9 kJ/mol?

Answer 1

To calculate the enthalpy change for the isomerization of 2-butene to 1-butene at constant pressure, we can use the following equation:H = Hf  products  - Hf  reactants In this case, the reactant is 2-butene and the product is 1-butene. The standard enthalpy of formation  Hf  for 2-butene is -118.0 kJ/mol and for 1-butene is -133.9 kJ/mol.H =  -133.9 kJ/mol  -  -118.0 kJ/mol H = -133.9 + 118.0H = -15.9 kJ/molThe enthalpy change for the isomerization of 2-butene to 1-butene at constant pressure is -15.9 kJ/mol.