CHEMISTRY 121 MIDTERM #2 CH 7-10 FEBRUARY 26, 2015 1. What are the main indicators that a chemical reaction has taken place? 2. How are soluble reactants and products indicated in a chemical equation? 3. In a chemical reaction, what is meant by the limiting reactant? 4. What does a thermochemical equation contain that a normal reaction does not? 5. How is the energy of a wave related to its wave length? 6. What happens when an element releases light to form an emission spectrum? 7. What is the requirement for two electrons to occupy the same orbital? 8. What types of bonds exist between two non-metals? 9. Predict the products and balance the following equations. a. Al + O2 b. C6H12O6 + O2 → c. Cl2 + AlBr3 → → 10. Using the solubility rules on the attached periodic chart, write the formula, ionic and net ionic equations, when Na3PO4 combines with Zn(NO3)2. 11. Give the electronic configuration, valence configuration and the number of valence electrons for the following a. N b. N3c. Pb2+ 12. Give the Lewis structure for the following: a. Cu b. Cu+ c. Cu2+ 13. Give a Lewis structure, draw the three dimensional structure, listing bond angles, geometrical shape and polarity for chloric acid HClO3. 14. Rust (Fe2O3) is often commercially removed using muriatic acid (HCl (aq) ): a. Write a balance an equation showing how rust is removed. b. Is 16.2 g of muriatic acid enough to remove 16.0 g of rust? (show work below) c. What is the theoretical yield of water? d. Which reactant is limiting? e. What is the percent yield if 3.55 g of water is recovered?