The pH scale

This is an introduction to the pH scale. Explore the relationship between pH and hydrogen ion (H⁺) concentration. Download PDF

Catalyst and Activation Energy

Catalyst A catalyst is a substance that speeds up a chemical reaction but it does not undergo a chemical reaction itself. The catalyst allows the reaction an alternative pathway to take place. The catalyst does not lower the activation energy of the reaction. Analogy

Bond Energy and Bond Enthalpy

Bond Enthalpy Introduction In order to understand why breaking bonds requires energy (endothermic) and making bonds releases energy (exothermic), one must first understand the nature of a chemical bond and why it occurs in the first place. Remember that bonds are due to the exchange or sharing of electrons between atoms. Forming bonds is a […]

Reaction enthalpies

Enthalpy change For a reaction Bonds Know that Breaking bonds always requires energy (never releases energy) Forming bonds always releases energy (never requires energy) Exothermic and endothermic process Breaking bonds is always an endothermic process (whether breaking single, double or triple bonds). Forming bonds is an exothermic process (whether making single, double or triple bonds). However, […]