Honors Chemistry - Unit 5 Chapter 7 - Nomenclature

Transcription

1 Honors Chemistry - Unit 5 Chapter 7 - Nomenclature Unit 5 Packet - Page 1 of 16 Vocab Due: Quiz(zes): 1) Test Date: UT Quest: 2) VOCABULARY: 1) monatomic ion 2) cation 3) anion 4) binary compound 4) ionic compound 5) transition metal 6) polyatomic ions 7) nomenclature 8) molecular compound 9)molecular formula 10) empirical formula FORMULAS/CONSTANTS/INFO TO BE MEMORIZED: Charges from periodic table; Common polyatomic ions; Numerical prefixes; Common Acids OBJECTIVES: Chapter 7 Understand how to find oxidation numbers from the periodic table and be able to use them in writing formulas. Memorize the common polyatomic ions. Be able to write and name ionic and molecular formulas. Be able to name transition compounds. Be able to identify the location of the metals and nonmetals on the periodic table. Be able to find oxidation numbers in compounds and polyatomic ions. Know the names of the families on the periodic table NOTE: acetate, ammonium, carbonate, nitrate, phosphate, and sulfate must be memorized! Highlight them! Others we will use: Peroxide: O2 2- Hydride: H 1- Mercury (I): Hg2 2+ Common Acids must be memorized! Hydrochloric Acid HCl Sulfuric Acid H2SO4 Nitric Acid HNO3 Phosphoric acid H3PO4 Acetic Acid HC2H3O2 Carbonic acid H2CO3

2 Unit 5 Packet - Page 2 of 16 Chapter 7 Chemical Formulas and Chemical Compounds 7-1 Chemical Names and Formulas I. Ionic Compounds (ionic bonds and formula units) VS. Molecules (covalent bonds and molecular formulas) A. Ionic compounds are composed of metals and nonmetals and are bonded together by ionic bonds. B. Molecules are composed of nonmetals and nonmetals and are bonded together by covalent bonds. C. Sample problems: circle the correct answers. 1. CaO2 is a(n) { ionic compound / molecule }. 2. The formula for CaO2 is known as a { formula unit / molecular formula } 3. CaO2 is bonded by { ionic / polar covalent / nonpolar covalent } bonds. 4. An oxygen molecule, O2, is a(n) { ionic compound / molecule }. 5. O2 is bonded by { ionic / polar covalent / nonpolar covalent } bonds. II. Chemical Formulas A. A chemical formula could be either a molecular formula or a formula unit. B. Either way, the chemical formula indicates the relative number of each atom in a chemical compound. C. Parentheses around a polyatomic ion identify it as one unit and any subscripts written next to parentheses apply to all the atoms inside the parentheses. D. Sample problems: circle or fill in the correct answers. 1. Butane, C4H10, is a(n) { ionic compound / molecule } that has carbon atoms and hydrogen atoms. 2. Aluminum oxide, Al2O3, is a(an) { ionic compound / molecule } that has aluminum ions and oxide ions in its simplest ratio. 3. Calcium chlorate, Ca(ClO3)2, has calcium ions Ca 2+, chlorate ions ClO3 -, chlorine atoms Cl, and oxygen atoms O. 4. Magnesium phosphate, Mg3(PO4)2, has magnesium ions Mg 2+, atoms O. phosphate ions PO4 3-, phosphorous atoms P, and oxygen

3 III. Naming monatomic cations alkali and alkaline-earth metals. Unit 5 Packet - Page 3 of 16 A. Naming ions for alkali and alkaline-earth metals is easy. Just use the element s name plus the word ion (or cation if you prefer). B. Complete the table: Atom Ion formed Ion name Li Na Mg Ca IV. Naming monatomic cations transition metals A. When naming ions for transition metals, the Stock system is used; a Roman numeral in parentheses is added to the name to indicate the charge of the ion. B. For example; Cu 1+ is copper(i) and Cu 2+ is copper(ii). C. Complete the table: Ion Ion name Pb 2+ Pb 3+ iron(iii) iron(ii) V. Naming monatomic anions nonmetals A. When naming anions for the nonmetals, drop the ending of the elements name and add the suffix ide. B. Complete the table; Atom Ion formed Ion name F I O N

4 VI. Unit 5 Packet - Page 4 of 16 Forming binary ionic compounds A. In a binary ionic compound the total positive charges must equal the total negative charges. The best way to write correct formula units for ionic compounds is to use the Criss Cross Method. B. Sample problem: What ionic compound would form when calcium ions combine with bromide ions? Steps to the Criss Cross Method: 1. Write the ions with their charges, cations are always first. Ca 2+ Br - 2. Cross over the charges by using the absolute value of each ion s charge as the subscript for the other ion. Ca Br2 3. Check to make sure the subscripts are in the lowest whole number ratio possible. Then write the formula. CaBr2 VII. Naming binary ionic compounds A. Combine the names of the cation and the anion. B. Example; BaBr2 is named barium bromide. C. First write the ions formed for the following elements. Then use the Criss Cross method to determine the formula. Then name the compounds. Elements Ions formed Formula Unit Name 1. magnesium and iodine 2. potassium and sulfur 3. chlorine and aluminum 4. zinc and bromine 5. sulfur and cesium 6. strontium and oxygen 7. calcium and nitrogen 8. calcium and oxygen 9. copper(i) and oxygen 10. copper(ii) and chlorine 11. mercury(ii) and oxygen 12. nitrogen and aluminum

5 Unit 5 Packet - Page 5 of 16 VIII. Naming binary ionic compounds that contain polyatomic ions A. The polyatomic ions on p. 210 and on your common ions list should be memorized. B. The most common oxyanions polyatomic anions that contain oxygen, end in ate. Oxyanions with one less oxygen end in ite. For example: NO3-1 is nitrate NO2-1 is nitrite SO4 2- is sulfate SO3 2- is sulfite C. Anions with one less oxygen than the ite ion are given the prefix hypo-. D. Anions with one more oxygen than the ate ion are given the prefix per-. ClO -1 is hypochlorite ClO2-1 is chlorite ClO3-1 is chlorate ClO4-1 is perchlorate E. Naming compounds with polyatomics is the same as naming other compounds, just name the cation and then the anion. If there is a transition metal involved, be sure to check the charges to identify which ion (+1, +2, +3, +4.) it may be so that you can put the correct Roman numeral in the name. Name the following. 1. NaOH 2. KClO3 3. Ca(NO3)2 4. NaCH3COO 5. NH4NO2 IX. Determining the formula unit when the compound has a polyatomic ion A. Use the Criss Cross Method. Parentheses are used around polyatomic ion if more than one polyatomic ion is present. Determine the formula for the following; Ions formed Formula unit 1. potassium hydroxide 2. ammonium acetate 3. potassium permanganate 4. iron(iii) nitrate 5. sodium sulfate

6 XI. Naming binary molecular compounds A. With molecules, the prefix system is used. Number Prefix 1 mono- 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta- 8 octa- 9 nona- 10 deca- Unit 5 Packet - Page 6 of 16 B. The less-electronegative element is always written first. It only gets a prefix if it has more that one atom in the molecule. C. The second element gets the prefix and the ending ide. D. The o or a at the end of the prefix is dropped when the word following the prefix begins with another vowel, for example monoxide or pentoxide. E. Name the following molecules. 1. As2O5 2. SF6 3. CO 4. N2O3 5. CI4 XI. Naming Acids A. Memorize the names and formulas for the following acids. HCl hydrochloric acid H3PO4 phosphoric acid HNO3 nitric acid H2SO4 sulfuric acid CH3COOH acetic acid H2CO3 carbonic acid Congratulations! You now know how to name compounds and molecules. All you have to do is practice. Additional Notes and Practice Examples are located on the chemistry classroom website.

7 Naming Compounds Flow Chart Chemical Formula Chemical Name Unit 5 Packet - Page 7 of Does it start with an H? Yes Is it Binary? (2 elements) Yes 1. Name like ionic compound THEN 2. Hydro ic Acid No 2. Does it have a metal and a nonmetal? No 1. Name like ionic compound THEN 2. Drop hydrogen ate goes to ic Acid ite goes to ous Acid No 1. It is a molecular compound! 2. Use prefixes to name it. Yes 3. It must be ionic! Is the cation in Group 1, 2 or Al, Zn, or Ag? 1. Cation Name plus Anion Name! Yes No 1. Cation name plus anion name. 2. Must calculate the charge on the cation! 3. Use Roman numeral to indicate the charge in the name.

8 Unit 5 Packet - Page 8 of 16 Writing Formulas with the Criss-Cross Method Write the formulas of the compounds produced from the listed ions.

9 Naming Ionic Compounds Unit 5 Packet - Page 9 of 16 Name the following compounds using the rules for naming ionic compounds.

10 Unit 5 Packet - Page 10 of 16 Naming Molecular Compounds Name the following covalent compounds using the rules for naming binary molecular compounds.

11 Write the formulas for the following compounds. Unit 5 Packet - Page 11 of 16 Writing Formulas from Names

12 Writing Chemical Formulas Mixed Practice Unit 5 Packet - Page 12 of 16 Use the nomenclature rules and the flowchart to write formulas for the following compounds: 1 calcium chloride 23 manganese (II) nitrate 2 calcium carbonate 24 chromium (III) sulfate 3 sodium cyanide 25 ammonium sulfide 4 magnesium oxide 26 iron (II) iodide 5 sodium fluoride 27 phosphorus dinitride 6 zinc iodide 28 dinitrogen monoxide 7 aluminum chloride 29 cerium (III) phosphate 8 rubidium acetate 30 sulfur trioxide 9 cobalt (II) chloride 31 barium nitrite 10 potassium hydride 32 chromium (III) nitride 11 copper (II) carbonate 33 lithium sulfite 12 potassium hydroxide 34 magnesium hydroxide 13 hydrogen bromide 35 dinitrogen trioxide 14 rubidium cyanide 36 strontium hydroxide 15 potassium fluoride 37 magnesium nitrate 16 calcium telluride 38 aluminum sulfate 17 manganese (III) oxide 39 potassium cyanide 18 magnesium phosphate 40 tin (IV) chloride 19 mercury (II) cyanide 41 dinitrogen tribromide 20 nickel (II) oxide 42 carbon tetrachloride 21 potassium nitrate 43 ammonium sulfide 22 sodium hydroxide 44 mercury (II) chloride

13 Writing Chemical Formulas Mixed Practice Unit 5 Packet - Page 13 of 16 Use the nomenclature rules and the flowchart to write formulas for the following compounds: 1 BaCl2 23 Na3PO4 2 Zn(NO3)2 24 NH4Cl 3 CsC2H3O2 25 NaCl 4 H2S (g) 26 NaNO3 5 K2CO3 27 (NH4)2SO4 6 FeCl3 28 Fe(NO3)3 7 Al(NO2)3 29 NaC2H3O2 8 NH4C2H3O2 30 BaSe 9 Ba(OH)2 31 CuSO4 10 Ca(C2H3O2)2 32 FeO2 11 NaOH 33 Cd3P2 12 HCl (aq) 34 N2O5 13 KCl 35 Co3(PO4)2 14 KBr 36 LiH 15 Ga2Te3 37 P2O3 16 Hg2Cl2 38 PCl5 17 CuSe 39 SF6 18 Pb(CN)2 40 PCl 19 HgI2 41 MgH2 20 NH4NO3 42 MnO 21 Na2SO4 43 P2O3 22 Na2O 44 HNO3

14 Assigning Oxidation Numbers: Unit 5 Packet - Page 14 of 16

15 Unit 5 Packet - Page 15 of 16

16 Review Sheet-Nomenclature Chemistry Unit 5 Packet - Page 16 of 16 Answer the following questions. 1. Give three examples of elements that are metals. 2. Give three examples of elements that are non-metals. 3. Give three examples of metalloids. Write the common oxidation number (charge) for the following monoatomic and polyatomic ions. 4. silver 5. alkali metals 6. halogens 7. chloride 8. carbonate 9. magnesium 10. nitrate 11. sodium 12. phosphate Write the chemical formula or name of each of the following compounds. Remember that a compound always has a neutral charge. 13. calcium chloride 27. Al2SO4 14. potassium chloride 28. NaF 15. lithium fluoride 29. Li2O 16. barium iodide 30. MgCl2 17. iron (II) nitrate 31. CuO2 18. beryllium carbonate 32. N2O5 19. barium chlorate 33 Find the oxidation numbers for the 20. cobalt (III) nitride elements in sulfuric acid 21. ammonium chloride 22. hydrochloric acid 23. potassium sulfate 24. rubidium phosphate 25. sodium acetate 26. carbon monoxide Answers: 1. various: Li, Na, Cu etc. 2. Various, F, Cl, He 3. Various, Si, As, Sb CaCl2 14. KCl 15. LiF 16. BaI2 17. Fe(NO3)2 18. BeCO3 19. Ba(ClO3)2 20. CoN 21. NH4Cl 22. HCl 23. K2SO4 24. Rb3PO4 25. NaC2H3O2 26.CO 27. aluminum sulfate 28. Sodium fluoride 29. Lithium oxide 30. Magnesium chloride 31. Copper (II) oxide 32. Dinitrogen pentoxide 33. H = 1+ S= 6+ and O = 2-