The Laws of Chemistry

Dalton's Atomic Theory A. Elements are composed of extremely small particles atoms called atoms. All atoms of the same element are alike, and atoms of different elements are different B. The separation of atoms and the union of atoms occur in chemical reactions. In these reactions, no atom is created or distroyed, and no atom of one element is converted into an atom of another element C. A chemical compound is the result of the combination of atoms of two or more elements in a simple numerical ratio

1.Law of conservation of mass states that there is no detectable change in mass during the course of a chemical reaction e.g. AgNO 3 + KIAgI + KNO g166 g235 g 101 g 336 g 336 g

2.Law of definite proportions states that a pure compound always contains the same elements in a fixed ratio e.g. Copper (II) oxide 1 g copper g oxygen

3.L aw of multiple proportions states that when two elements form more than one compound the amounts of one element that are combined with a fixed amount of the other element are in a small whole - number ratio Name% oxygen g Ratio nitrogenoxygen 1g nitrogen Dinitrogen oxide Nitrogen oxide Dinitrogen trioxide Nitrogen dioxide Dinitrogen pentoxide

4.G ay - Lussac's law of combining volums states that the volums of gases the are used or produced in a chemical reaction can be expressed in ratios of small whole numbers (const. temp. and p.) e.g. 1 volume hydrogen + 1 volume chlorine 2 volumes hydrogen chloride H 2 (g) + Cl 2 (g) 2HCl (g) The law is applicable only to gases!

5.A vogadro's principle (law) equal volumes of all gases at the same temperature and pressure contain the same number of molecules