AP Chemistry - Unit 6 - Thou Shall Not Forget

Front

What is the formula for calculating enthalpy change (ΔH) using bond energies?

Back

ΔH = Bond broken - Bonds formed

Front

According to Hess' Law, what happens to ΔH if you double the coefficients of a reaction?

Back

ΔH will double.

Front

In the equation ΔH_rxn = ΔH_{_________________} - ΔH_{_________________}, what fills the blanks?

Back

products, reactants

Front

What is bond enthalpy?

Back

The amount of energy required to break one mole of a bond.

Front

What does an exothermic reaction do?

Back

Release energy.

Front

What is the relationship between bond energies and enthalpy change?

Back

Enthalpy change can be calculated by subtracting the total bond energies of the products from the total bond energies of the reactants.

Front

What is Hess' Law?

Back

The total enthalpy change for a reaction is the sum of the enthalpy changes for the individual steps of the reaction.

Front

What is the significance of bond formation in terms of energy?

Back

Bond formation releases energy, contributing to the stability of the resulting molecule.

Front

How do you determine if a reaction is endothermic or exothermic?

Back

If ΔH is positive, the reaction is endothermic (absorbs energy); if ΔH is negative, the reaction is exothermic (releases energy).

Front

What is the standard enthalpy of formation?

Back

The change in enthalpy when one mole of a compound is formed from its elements in their standard states.