Unit 4 review for finals

Transcription

1 Unit 4 review for finals These are the topics you should know and be able to answer questions about: 1. Types of compounds a. What are the four types of bonding? Describe each type of bonding. i. Ionic Bonding (Metal + Nonmetal) ii. Covalent Bonding (Nonmetal + Nonmetal) iii. Polyatomic Bonding (Both Ionic and Covalent Characteristics > 3 or more elements including metal and nonmetals) iv. Metallic Bonding (One type of metal atom) b. Draw a picture of an ionic compound. Ionic compounds are 3D cubes c. Which of the following sets of ions would have the strongest attraction to each other in an ionic compound: i. Na + + Cl - ii. Ba 2+ + O 2- iii. Na + + Ba 2+ Option ii would have the strongest attraction. We know that opposite charges attract each other and the larger the charge, the larger the attraction. d. Draw a picture of a covalent compound. e. What are properties of ionic compounds? i. Bond between a Metal (Cation) and a Nonmetal (Anion) ii. Involves the TRANSFER OF ELECTRONS iii. Interaction between ions (atoms with a charge) iv. Compounds held together by electrical charges v. Bond gets stronger as magnitude of charges increase vi. Na + and Cl - weaker than Mg 2+ and O 2-

2 vii. Ionic compounds commonly known as salts viii. Ex: NaCl Table Salt ix. Solid at room temperature x. High melting and boiling points xi. Due to strong electrostatic interaction between (+) and (-) charges xii. Conduct electricity when molten xiii. When dissolved in water, they are strong electrolytes xiv. Ionic compounds do not exist as individual molecules, but rather as a group of molecules xv. Basic structure of an ionic compound is a lattice-work of oppositely charged particles f. What are properties of covalent compounds? i. A.K.A. Molecular Bonds ii. Nonmetal + Nonmetal iii. NOT composed of ions! iv. Involves SHARING OF ELECTRONS v. Involves multiple bonds vi. Single, Double, or Triple vii. Shown by dashes to indicate shared pairs of e- viii. Relatively low melting points and boiling points ix. DO NOT conduct electricity when molten x. When dissolved in water, can be strong electrolytes, weak electrolytes, or nonelectrolytes xi. Covalent compounds exist as individual molecules that have a definite composition xii. They are held together by attractions of SHARED ELECTRONS g. What are properties of polyatomic compounds? i. Polyatomic ions look like molecules but they have an overall charge ii. The group of elements, together, have too many electrons or too little electrons iii. Therefore they have a positive or negative charge iv. Characteristics of Polyatomics v. Polyatomic ions are usually a result of a covalent bond between 2 elements vi. Ex: O + H OH - vii. Because of its charge, it then forms an ionic bond with other elements or compounds viii. Ex: OH - + Na + NaOH Metals: Bonding that takes place between only one kind of metal atom Structure is similar to ionic compound structure Lattice-work structure Only one kind of atom h. What are the differences between an ionic and covalent compounds? i. What types of elements are they composed of? 1. Ionic = metal and nonmetal 2. Covalent = 2 nonmetals ii. What happens to the electrons in each type of compound? 1. Ionic = the electrons are transferred from the metal to the nonmetal 2. Covalent = the two nonmetals share the electrons iii. What are the properties of the two types of compounds? 1. SEE ABOVE

3 iv. Which type conducts when dissolved in water? 1. Ionic compound i. Which of the following pictures is ionic? Which is covalent? This is 1 ionic compound This is a picture of 16 covalent compounds j. Which of the following pictures below is an ionic compound? Contains a covalent compound? Contains a metallic compound? Is a pure substance? Is a mixture? Solid gas liquid solid Ionic compound covalent compound element metallic compound Pure substance pure substance compound pure substance mixture Solid gas solid gas gas gas ionic compound covalent cmpd metallic cmpd covalent cmpd element molecule Pure substance molecule pure substance pure substance molecule Mixture mixture

4 2. What is an ionic compound? Give an example. a. Know how to write ionic formulas: Ca + F 1. Use your t chart CaF2 Rubidium and Oxygen 1. Rb + O = Rb2O b. Remember metals with a positive charge are always written first in the molecule i. What compound would be formed when A 2+ bonds with B -3? 1. A3B2 3. Know how to name ionic compounds: NaBr o Sodium bromide K2O o Potassium oxide 4. Know how to write ionic formulas with polyatomics: Cs + NO3 o Cs(NO3) Aluminum Acetate o Al + C2H3O2 Al(C2H3O2)3 5. Know how to name ionic compounds with polyatomics: Li2CO3 o Lithium carbonate Be3(PO4)2 o Beryllium phosphate 6. Know how to write ionic formulas with transition metals: Copper (II) Nitrate o The roman numeral means that charge of the metal o Use your t chart Cu(NO3)2 Iron (III) Oxide o Fe2O3 7. Know how to name ionic compounds with transition metals: HgCl2 o Mercury (II) chloride CoSO3 o Cobalt (II) sulfite o What do the numbers inside the parentheses after a transition metal mean? They are the charge of the transition metal

5 8. What are the charges for Ag, Zn, and Cd? Ag = +1 Zn = +2 Cd = +2