purity and formulations

• pure substance - contains only one type of compound or element
• pure substances melt and boil at specific temperatures
• impure substances don't have fixed melting or boiling points
• impurities in a substance will lower the melting point
• impurities in a substance will increase boiling point
• formulations are mixtures prepared using a specific formula. They are made from precise amounts of different components each with a particular function