Presentation on theme: "General Chemistry Zumdahl Chapter 7 Notes Chemical Reactions"— Presentation transcript:
1 General Chemistry Zumdahl Chapter 7 Notes Chemical Reactions Week of 1/26/15, Expected test date, Tuesday 2/3/15Standard: HS-PS1-7 Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
2 Introduction Where do we see chemical reactions?(1) Everywhere! Cars driving, hair growing, clothes being made, etc…
3 7.1 Evidence for a Chemical Reaction p. 193 of book Most chemical reactions give a visual signal when they occur.What are some examples of these visual changes?(2)Color changePrecipitate (solid) formsGas is formed (bubbles)A flame forms
4 7.2 Chemical Equations, p. 195 Define Chemical reaction(3): Atoms of different compounds are rearranged forming new compoundsChemical equation(4): A visual representation of a chemical reactionReactant(5): Chemicals before the reactionProducts(6): Chemicals after the reaction
5 7.2 Chemical Equations What are the abbreviations for Solid (7): (s) Liquid (8): (l)Gas (9): (g)Dissolved in water or aqueous (10): (aq)
6 7.3 Balancing Chemical Equations, p. 200 It is important to understand that in a chemical reaction atoms are neither created nor destroyed.There are the same amount of each atom on the reactant side as there are on the product side.
7 7.3 Balancing Chemical Equations The burning of methane gas produces carbon dioxide and waterCH4(g) + O2(g) CO2(g) + H2O(l)What is wrong with this?(11)Not balanced!CH4(g) + 2O2(g) CO2(g) + 2H2O(l)
8 7.3 Balancing Chemical Equations The chemical formation of waterH2(g) + O2(g) H2O(l)What is wrong with this?(12) Not balanced2H2(g) + O2(g) 2 H2O(l)Define coefficient(13): The number of compounds that is needed to make equation balanced.