Properties: Chemical -exhibited by matter as it undergoes changes in composition

1. Properties: Chemical-exhibited by matter as it undergoes changes in composition Physical-exhibited by matter without a change in composition. Color, state, density, melting point, boiling point, etc. Extensive-depends on the amount of matter (i.e. mass, heat capacity...) Intensive-independent of the amount of matter (color, state, density, chemical properties,...) 2Mg + O2-----> 2MgO Physical & Intensive:

2. Chemical Change-one or more substances are either used up or formed and energy is absorbed or released. (Rxn’s) 2Mg + O2 2MgO Physical Change-change in physical properties without a change in composition.

3. Physical Change ChemicalChange H2 O2

4. SI=International System of Units Length = meter Volume = m3 Mass = kg Temperature = K (Kelvin) Time = s (seconds) Energy = J (Joule) K=oC+273.15

5. Parts of A (by mass) 100 parts mixture (by mass) % Composition %A (mass)= mass (g) volume (ml) Density (density)= Specific Gravity (substance) (water) (water)=1.00 g/ml @ 25oC =Sp. Gr.= (Amount of heat in J) (mass of substance in g)(Temperature change in K/oC) Specific Heat = Heat Capacity= (Csp)(mass) units=(J/ oC) Purity is given by the % Composition

6. Stoichiometry Composition Stoichiometry-Quantitative relationship among elements in a compound. (H2O; 2 H atom and 1 O atom per 1 H2O molecule) Reaction Stoichiometry-Quantitative relationship among substances as they undergo chemical changes. (P4+6Cl2 4PCl3; 1P4 molecule reacts with 6Cl2 molecules to produce 4 PCl3 molecules) Dalton’s Atomic Theory: 1) An element is composed of extremely small, indivisible particles called atoms 2) All atoms of a given element have identical properties 3) Atoms cannot be created, destroyed or transformed into atoms of another element. 4) Compounds are formed when atoms of different elements combine with one another in small whole-number ratios. 5) The relative numbers and kinds of atoms are constant in a given compound.

7. Atom-the smallest particle of an element that maintains its chemical identity through all chemical and physical changes and are composed 3 fundamental particles-electrons, protons and neutrons Molecule-the smallest particle of an element or compound that can have a stable independent existence. Diatomic molecules - O2, N2, H2, F2, I2, Br2, Cl2 .....(Know these) Formula units: Ionic Compounds-consistsof an extended array of ions Know Table 2-3 in the book Cation=positively charged ion anion=negatively charged ion

8. Know how to calculate the MW/FW of any molecule/formula unit example: MW of water = 18.0 amu/molecule = 18.0 g/mol 2*AW(H)+AW(O)=MW (2*1.01)+(16.0)=18.0 FW sodium chloride = 58.4 amu/formula unit=58.4 g/mol AW(Na) + AW(Cl)=FW 23.0 + 35.4 = 58.4 1 mol= 6.022*1023 particles just a unit conversion Stoich. NA MW g mole mole particles mole X mol Y

9. Empirical (Simplest) Formula - The smallest whole-number ratio of atoms present in a compound. Molecular Formula of Caffeine = C8O2N4H10 Empirical Formula of Caffeine = C4ON2H5 The Empirical Formula is found by determining the % composition experimentally. The Molecular Formula is determined from the Empirical Formula and the experimentally determine Molecular Weight. MW EW n=

10. You should be able to determine if a chemical reaction is balanced and if it isn’t, you should be able to balance it. You should be able to answer questions like: given the mass of CS2 and excess O2 how many grams of CO2 or SO2 will be produces? given the mass of CS2 and the mass of O2 how many grams of CO2 or SO2 will be produced? Which reactant is the limiting reagent (reactant)?