CHEM 1000 Lecture Notes - Lecture 8: Molar Mass, Chemical Equation, Chemical Formula
Document Summary
Section 5. 1-5. 4 balancing chemical equations; molar mass; percent composition; Chemical equations describe a chemical change using symbols and formulas to represent the elements and compounds involved in a chemical reaction. Carbon reacts with oxygen to form carbon dioxide ( c + o2 = co2) Symbols: (s) = solid (l) = liquid (g) = gas (aq) = aqueous solution (aqueous = water) Coefficients numbers used to balance a chemical equation. These numbers are placed in front of the molecular formula. Molar mass mass (in grams) of one mole of a substance; sum of the atomic masses for all atoms in a molecular formula (atomic mass x number of atoms = molecular mass) Percent composition by mass a chemical formula represents the ratio of atoms as well as a ratio of mass. [(atomic mass x number of atoms) / total molar mass of the compound] x 100 = Stoichiometry greek stoicheion means element metry means to measure.
