Chapter 10 Standard Enthalpy of Formation & Bonding Energy

What are standard conditions for gases? 1 atm pressure.

What are standard conditions for solutions? 1 M concentration.

What does the ° symbol indicate? Standard conditions.

What does the subscript f in ΔHf° mean? Formation.

What is the equation for standard reaction enthalpy? ΔH°rxn = ΣnΔHf°(products) − ΣmΔHf°(reactants).

What do the coefficients n and m represent? Stoichiometric coefficients.

What information is needed to calculate ΔH°rxn? Standard enthalpies of formation.

What must be multiplied by stoichiometric coefficients? The ΔHf° values.

What is bond enthalpy? The energy required to break a bond.

What does a large bond enthalpy indicate? A stronger bond.

What happens when bonds break? Energy is absorbed.

What happens when bonds form? Energy is released.

What is lattice energy? The energy associated with forming an ionic solid from gaseous ions.

What does a larger lattice energy indicate? A more stable ionic compound.

Why are ionic compounds often very stable? Because of strong electrostatic attractions between ions.