What drives chemical reactions?: notes and practice questions

This topic covers the measurement and interpretation of energy changes in chemical and physical processes. Chemical reactions involve energy transfer between the system and surroundings, with total energy conserved.

This topic covers how the law of conservation of energy helps predict energy changes in chemical reactions. Bond breaking is an endothermic process, absorbing energy.

This topic covers the energy released from fuels through combustion and the operation of fuel cells. Elements, compounds, and organic compounds like hydrocarbons and alcohols undergo combustion reactions.

This topic covers the application of Hess's law using standard enthalpy changes of formation and combustion, and the interpretation of Born-Haber cycles for ionic compounds. The standard enthalpy change of a reaction can be calculated using standard enthalpies of formation: $\Delta H^\ominus = \Sigma(\Delta H_\text{f}^\ominus \text{ products}) - \Sigma(\Delta H_\text{f}^\ominus \text{ reactants})$.

This topic covers the higher level extension of energy from fuels. The IB Chemistry guide explicitly states "Additional higher level: None for Reactivity 1.3".

This topic quantifies entropy and Gibbs energy to predict reaction spontaneity and equilibrium. Entropy, $S$, is a measure of matter and/or energy dispersal; calculate standard entropy changes, $\Delta S^\ominus$, from standard entropy values.