Pre AP Compound Practice Exam 2006

Pre AP Compound Practice Exam 2015 These are the objectives for the unit. Read over them and think of ways they could be tested. 1. Understand why atoms bond to form stable electron configurations 2. Differentiate between ionic and covalent bonds and predict the type of bond between elements using electronegativity values 3. Identify, write, and name ionic compounds given elements or polyatomic ions and a periodic table 4. Understand and use polyatomic ions in formulas; memorize common polyatomic ions 5. Identify, write, and name molecular compounds given elements and atomic or mass ratios 6. Write electron dot diagrams and use these to predict single, double, and triple bonds 7. Calculate molar mass of compounds and complete mole calculations. 8. Predict and list chemical and physical properties of ionic and molecular compounds 9. Compare the arrangement of atoms in molecular, ionic crystals, polymers, amorphous, and metallic substances 10. Predict molecular geometry using VESPER 11. Understand and describe metallic bonds and alloys 12. Conceptualize and calculate percent composition of elements in compounds as well as other macro examples Complete the following free response questions. 1. List four properties of ionic compounds:

2. How can you identify a binary molecular compound from the name/formula?

3. Why is it important to use roman numerals like II or IV when naming an ionic compound with a transition metal?

4. Describe the actions of the valance electrons in metallic bonds.

5. In a covalent/molecular bond, electrons are ______while in an ionic bond electrons are ______or ______. 6. Non-metals tend to ______electrons and become ______in ionic bonding.

7. Atoms want a full outer energy level. For most atoms, this is ______electrons which is why this is called the ______rule.

9. Give the molar mass for the following compounds.

a. H2SO4 b. C2H2 c. Ba(OH)2

10. Draw an electron dot diagram to predict the type of bonding and the number of

bonds between two atoms of nitrogen in the diatomic molecule N2.

11. Name the following compounds:

1. Li2S 6. N7S8

2. CO3 7. PbO

3. CuBr 8. FeBr3

4. Cu2O 9. Ba(CN)2

5. Na2SO4 12. Write the formulas for the following compounds:

6. lithium carbonate 5. cupric sulfate

7. potassium cyanide 6. dihydrogen monoxide

8. tin (IV) chlorite 7. Lead (II) iodide

9. beryllium oxide 8. ammonium sulfate

13. What is meant by the term polar? How can you tell if a bond it polar covalent, nonpolar covalent or ionic?

14. Calculate the mass of 1.25 moles of LiCl

2.57 x 1023 molecules of water

15. Find the % oxygen by mass in water.

16. If a compound consists of 38.7 % C, 16.1 % H and 45.2 % N, what is the empirical formula?

Complete the following multiple choice questions by choosing the best answer. 17. There are _____ paired and _____ unpaired electrons in the Lewis symbol for a phosphorus atom. a. 4, 2 b. 2, 4 c. 2, 3 d. 4, 3 e. 0, 3

18. Based on the octet rule, magnesium most likely forms a _____ ion. a. Mg2+ b. Mg2- c. Mg6- d. Mg6+ e. Mg-

20. Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration? O Sr Na Se Br a. Br b. Sr c. Na d. O & Se e. Sr, O, & Se

21. Elements from opposite sides of the periodic table tend to form ______. a. covalent compounds b. ionic compounds c. compounds that are gaseous at room temperature d. homonuclear diatomic compounds e. covalent compounds that are gaseous at room temperature 22. How many single covalent bonds must a silicon atom form to have a complete octet in its valence shell? a. 3 b. 4 c. 1 d. 2 e. 0

23. Compounds consisting entirely of nonmetals ______. a. are noble gases b. are ionic c. do not exist d. are molecular e. are always solid at room temperature

24. A double bond consists of _____ pairs of electrons shared between two atoms. a. 1 b. 2 c. 3 d. 4 e. 6

25. What is the maximum number of double bonds that a hydrogen atom can form? a. 0 b. 1 c. 2 d. 3 e. 4

26. The central atom in _____ violates the octet rule. a. ClF3 b. PCl3 c. SO3 d. CCl4 e. CO2

27. The Lewis structure of the CO2 molecule has ____ double bond(s). a. 0 b.1 c. 2 d. 3 e. 4

28. The basis of the VSEPR model of molecular bonding is ______. a. regions of electron density on an atom will organize themselves so as to maximize s-character b. regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap c. atomic orbitals of the bonding atoms must overlap for a bond to form d. electron pairs in the valence shell of an atom will arrange themselves so as to minimize repulsions e. hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry

29. The electron-domain geometry of _____ is tetrahedral. a. CBr4 b. PH3 c. CCl2Br2 d. XeF4 e. all of these except XeF4

30. The molecular geometry of the SF2 molecule is ______. a. linear b. bent c. trigonal planar d. tetrahedral e. octahedral

Fill in the missing name or formula: Name Formula calcium chloride ______barium nitride ______silver oxide ______iron(II) oxide ______lithium sulfate ______barium nitrate ______dinitrogen pentoxide ______calcium acetate ______water ______ammonia ______magnesium sulfate ______

______Ca3P2

______CBr4 ______KCl

______Na2CO3

______Al2O3

______FeBr2

______Sn(ClO3)4

______NO2 ______AgBr

______NaNO3

______CuCl2

Find the molar mass of the following compounds:

lithium sulfate ______

barium hydroxide ______

magnesium acetate ______