Exam R 12 pm Review T 2 SL120. NO GRAPHING CALULATORS!!!!!!!!!

1. Exam R 12 pm Review T 2 SL120. NO GRAPHING CALULATORS!!!!!!!!!

2. Figure 2.16: Molecular and structural formulas and molecular models.

3. Ethanol

4. Fig. 2.18

5. Figure 2.19: A model of a portion of NaCl.

6. The Periodic Table of the Elements Most Probable Oxidation State +1 0 +2 +3 +_4 - 3 - 2 - 1 H He Li Be B C N O F Ne +3 +4 +5 +1 + 2 Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cu Zn Ga Ge As Se Br Cr Mn Fe Co Ni Kr Rb Sr Zr Nb Ag I Mo Tc Ru Rh Pd Xe Y Cd In Sn Sb Te Ba Au Hg W Re Os Ir Pt Rn Cs La Hf Ta Tl Pb Bi Po At Fr Ra Ac Rf Du Sg Bo Ha Me +3 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr +3

8. Fig. 2.20

11. Don’t use these when naming ionic compounds--they’re ONLY for covalent compounds!!

12. Chemical Formulas Empirical Formula- Shows the relative number of atoms of each element in the compound. It is the simplest formula, and is derived from masses of the elements. Molecular Formula - Shows the actual number of atoms of each element in the molecule of the compound. Structural Formula - Shows the actual number of atoms, and the bonds between them ; that is, the arrangement of atoms in the molecule.

13. Figure 2.23: Molecular model of nitric acid. What is the formula for nitric acid? HNO3

15. Conceptual Problem 2.26: model of water, KCI, methanol, ammonia. water ammonia ethanol potassium chloride

16. Conceptual problem 2.63: Ball and stick model of hydrogen, oxygen, and carbon. C3H6O2 PCl5 NO2

17. Problem 2.64: Models of sulfuric acid, benzene, and 2-propane.

19. Figure 2.28: Representation of the reaction of methane with oxygen. Write a balanced chemical reaction for this combustion reaction. CH4(g) + 2 O2 (g) 2 H2 O(l) + CO2(g) Write this reaction in words: Methane gas plus 2 oxygens make 2 waters and one carbon dioxide

20. Figure 2.26: The burning of propane gas. Photo courtesy of American Color. Write a balanced equation for this combustion reaction. The products are carbon dioxide and water. First write the reaction. C3H8 + O2  H2O + CO2 Then balance it. C3H8 + 5 O2  4 H2 O + 3 CO2 Then add physical states. C3H8 (g) + 5 O2 (g)  4 H2 O (l) + 3 CO2 (g)

21. Figure 3.3: Reaction of zinc and iodine causing iodine to vaporize.Photo courtesy of James Scherer.

22. Chemical Equations Qualitative Information: Reactants Products States of Matter: (s) solid (l) liquid (g) gaseous (aq) aqueous 2 H2 (g) + O2 (g) 2 H2O (g)

23. Balanced Equations • mass balance (atom balance)- same number of each element(1) start with simplest element(2) progress to other elements (3) make all whole numbers (4) re-check atom balance • charge balance (no “spectator” ions) 1 CH4 (g) + O2 (g) 1 CO2 (g) + H2O (g) 1 CH4 (g) + O2 (g) 1 CO2 (g) + 2 H2O (g) 1 CH4 (g) + 2O2 (g) 1 CO2 (g) + 2 H2O (g) Ca2+ (aq) + 2 OH- (aq) Ca(OH)2 (s) + Na+ + Na+

24. C6H14 (l) + O2 (g) CO2 (g) + H2O(g) + Energy Balancing Chemical Equations - I Problem: The hydrocarbon hexane is a component of Gasoline that burns in an automobile engine to produce carbon dioxide and water as well as energy. Write the balanced chemical equation for the combustion of hexane (C6H14). Plan: Write the skeleton equation from the words into chemical compoundswith blanks before each compound. begin the balance with the most complex compound first, and save oxygen until last! Solution: C6H14 (l) + O2 (g) CO2 (g) + H2O(g) + Energy Begin with one Hexane molecule which says that we will get 6 CO2’s! 1 6

25. C6H14 (l) + O2 (g) CO2 (g) + H2O(g) + Energy 2 C6H14 (l) + O2 (g) CO2 (g) + H2O(g) + Energy 12 14 2 C6H14 (l) + O2 (g) CO2 (g) + H2O(g) + Energy 12 14 Balancing Chemical Equations - II The H atoms in the hexane will end up as H2O, and we have 14 H atoms, and since each water molecule has two H atoms, we will get a total of 7 water molecules. 1 6 7 Since oxygen atoms only come as diatomic molecules (two O atoms, O2),we must have even numbers of oxygen atoms on the product side. We do not since we have 7 water molecules! Therefore multiply the hexane by 2, giving a total of 12 CO2 molecules, and 14 H2O molecules. This now gives 12 O2 from the carbon dioxide, and 14 O atoms from the water, which will be another 7 O2 molecules for a total of 19 O2 ! 19

26. Predicting the Ion an Element Will Form in Chemical Reactions Problem: What monoatomic ions will each of the elements form? (a) Barium(z=56) (b) Sulfur(z=16) (c) Titanium(z =22) (d) Fluorine(z=9) Plan: We use the “z” value to find the element in the periodic table and which is the nearest noble gas. Elements that lie after a noble gas will loose electrons, and those before a noble gas will gain electrons. Solution: (a) Ba+2, Barium is an alkaline earth element, Group 2A, and is expected to loose two electrons to attain the same number of electrons as the noble gas Xenon! (b) S -2, Sulfur is in the Oxygen family, Group 6A, and is expected to gain two electrons to attain the same number of electrons as the noble gas Argon! (c) Ti+4, Titanium is in Group 4B, and is expected to loose 4 electrons to attain the same number of electrons as the noble gas Argon! (d) F -, Fluorine is in a halogen, Group 7A, and is expected to gain one electron, to attain the same number of electrons as the noble gas Neon!