CHM 1311 Lecture Notes - Lecture 3: Stoichiometry, Spectator Ion, Molality

• School: University of Ottawa
• Department: Chemistry
• Course: CHM 1311
• Professor: Wendy Pell

Document Summary

Chemical formulas: the identity and ratio of elements in which a molecule is expressed. Molecular formula shows exact # and ratio of each element: i. e h2o water, o2 oxygen. Structural formula shows how atoms are bonded together using a line to represent a bond: i. e h-o-h water. Empirical formula shows the simples whole # ratio of elements: i. e hydrogen peroxide molecular formula h2o2; empirical formula ho. Avogadro"s number (the mole): 1 mole is defined as the number of 12c atoms found in exactly 12g of 12c (6. 02214 x 1023) An amount of a substance that contains the same number of elementary entities as there are carbon-12 atoms in exactly 12g of carbon-12. Molar mass: mass in g of 1 mol (6. 02214 x 1023 atoms or molecules) of a substance; also the mass # for the element in the periodic table i. e molar mass of 12c = 12. 0000gm=m/n.