Summary
Highlights
Standard enthalpy change of formation is the enthalpy change when one mole of a compound is formed from its elements in their standard states under standard conditions.
The video demonstrates calculating the enthalpy change for the combustion of propane (C3H8). The formula used is: ΔH°reaction = ΣΔH°f (products) - ΣΔH°f (reactants). Standard enthalpy change of formation values can be found in data booklets, and importantly, elements like O2 have a standard enthalpy change of formation of zero.
The video walks through the calculation step-by-step, using specific values for CO2, H2O, and C3H8, and noting that O2 is not included as its value is zero. The resulting standard enthalpy change of reaction is calculated to be -2221 kJ/mol.
The video concludes by showing how to write an equation for the formation of one mole of a compound from its elements, using ethanol (C2H5OH) as an example. This involves balancing the elements to form one mole of the desired compound.