CHEM1011 Lecture Notes - Lecture 3: Ionic Compound, Chemical Equation, Carbon-12
Document Summary
In an ionic solid, the ions bond together strongly owing to their opposite charges (e. g. na+ and cl-) Ionic solids dissolve in water because the breaking of ion-ion attractions of the solid is compensated for by h2o molecules forming strong bonds to each individual ion (solvation). Also favouring dissolving: ions in solution can move randomly in the bigger volume of liquid (increase randomness). Stoichiometry is concerned with the relative amounts of reactants and products in a chemical reaction (law of multiple proportions). Stoichiometric coefficients indicate the simplest ratio of molecules, ions or atoms among the reactants and products. The law of conservation of mass says that atoms cannot be created or destroyed during a chemical reaction. In balancing an equation, the numbers within each chemical species cannot be changed. This would be changing the identities of the chemicals involved. Coefficients can be changed to balance the equation.