Calculate How much heat is released by the combustion of 206 g of hydrogen gas? H comb = -286 kJ/mol
Predicating a chemical reaction l Formation of a solid l Formation of water l Transfer of electrons l Formation of a gas l Change in heat energy is observed or felt through heat or light l Exothermic: heat is released l Endothermic: heat is absorbed l Permanent color change Catalyst: if one is added to a reaction, the reaction goes faster but the catalyst does not become part of the reaction Precipitation: a chemical reaction that forms a solid l Precipitate: solid that forms l Precipitation reaction: the reaction l Ionic compound dissolved in water l When a solid containing ions dissolves in water, the ions separate and move around independently l Ions must be present in water for a current to flow l Strong electrolyte: a substan
