2. Chemical Reactions Chapter 7

3. Review….Count The Atoms CaCl 2 Zn(NO 3 ) 2 2NaOH 3H 2 O One Calcium/2 Chlorine 1 Zinc/2Nitrogen/6Oxygen 2 Na, 2 O, 2 H 6 H, 3 O

4. Anatomy of a Chemical Reaction CH 4 (g) + 2O 2 (g) CO 2 (g) + 2H 2 O (g) Reactants SUBSCRIPT: Tells how many atoms there are of an element PLUS SIGN: Used to separate each reactant or each product FORWARD ARROW: Means produces or yields, etc. DELTA: Shows that heat is supplied to the reaction ITALICIZED ABBREVIATION: Tells what physical state that reactant or product is in COEFFICIENT: Tells how many of each reactant or each product there is (g): reactant or product in gaseous state (s): reactant or product in solid state (l): reactant or product in liquid state (aq): designates an aqueous solution; substance dissolved in water SYMBOLSSYMBOLS : Products

5. Anatomy of a Chemical Reaction cont’ Zn (s) + 2HCl (aq) ZnCl 2 (aq) + H 2 (g) 2KI (aq) + Pb(NO 3 ) 2 (aq) 2K(NO 3 )(aq) + PbI 2 (ppt)

6. Anatomy of a Chemical Reaction ….. 2H 2 O 2 (aq) O 2 + 2H 2 0 (l) I-I- Catalyst: Speeds up reaction without participating in rxn Hydrogen Peroxide reacts to form Oxygen gas and water IN WORDS… 2SO 2 (g) + O 2 (g) 2SO 3 (g) DOUBLE ARROW: Reaction is reversible IN WORDS… Gaseous Sulfur Dioxide reacts with Oxygen gas to form gaseous Sulfur Trioxide

7. (The Diatomic Elements!!!)

8. Writing Equations….. **Write the Following Equations…. 1. Solid Sulfur burns in oxygen gas to form sulfur dioxide gas S(s) + O 2 (g) SO 2 (g) 2.Oxygen gas can be made by heating potassium chlorate in the presence of a manganese (IV) oxide catalyst. Potassium chloride is left as a solid residue 3.When solid mercury (II) sulfide is heated with oxygen, liquid mercury metal and gaseous sulfur dioxide are produced.

9. Writing Equations… 2. KClO 3 (s) O 2 (g) + KCl(s) 3. HgS(s) + O 2 (g) Hg(l) + SO 2 (g) ∆ MnO 2 Describe in words: NaHCO 3 (s) + HCl (aq) NaCl (aq) + H 2 O(l) + CO 2 (g) When solid sodium bicarbonate reacts with a solution of hydrogen chloride (hydrocholoric acid), it forms aqeuous sodium chloride, water, and carbon dioxide gas.