Chemical Properties and Chemical Changes

Chemical Changes A chemical change results in a new substance (or new substances) being produced - as a result of a chemical reaction. Ex/ Iron rusting – (rust is a new substance)

Signs of Chemical Change 1.Bubbles/Fizzing (Gas produced) 2.Energy change (temperature, sound, light) 3.Odor change 4.Color change 5.Precipitate (Production of a solid from solution) *Not all signs will be present for every chemical change *These signs do not ALWAYS indicate a chemical change

Chemical Properties A chemical property is a characteristic that determines how a substance will react with other substances or change from one substance to another (the ability or inability of a substance to react/change) Ex: Some chemical properties of water are that it does not react with gold and it does react with sodium These properties can only be observed when a substance undergoes a chemical change

Acids If a substance is an acid, it will have certain chemical and physical properties: – Physical properties: taste sour – Chemical properties: acids change litmus from blue to red react with bases to form salts and water react with some metals are corrosive (“eat away” materials)

Bases If a substance is a base, it will have certain chemical and physical properties: – Physical properties: taste bitter feel slippery – Chemical properties: change litmus from red to blue react with acids to form salts and water