Unit 6 Ionic Compounds

Transcription

1 Unit 6 Ionic Compounds Early Booklet E.C.: / 2 Unit 6 Hwk. Pts: / 24 Unit 6 Lab Pts: / 10 Late, Incomplete, No Work, No Units Fees? Y / N Learning Targets for Unit I can define chemical bond 1.2 I can describe the formation of positive and negative ions 1.3 I can relate ion formation to electron configuration 1.4 I can describe the formation of ionic bonds and the structure of ionic compounds 1.5 I can generalize about the strength of ionic bonds based on the physical properties of ionic compounds 1.6 I can categorize ionic bond formation as exothermic or endothermic 1.7 I can relate a formula unit of an ionic compound to its composition 1.8 I can write formulas for ionic compounds and oxyanions 1.9 I can apply naming conventions to ionic compounds and oxyanions 1.10 I can describe a metallic bond 1.11 I can relate the electron sea model to the physical properties of metals 1.12 I can define alloys, and categorize them into two basic types. Unit Vocabulary for Unit 6 Anion Cation Chemical bond Crystal lattice Electrolyte Ionic bond Ionic compound Lattice energy Formula unit Monatomic Ion Oxidation number Oxyanion Polyatomic ion Binary Compound Delocalized electron Electron sea model Metallic bond 69

2 Possible 6.1 Pts.: 6 Late, Incomplete, No work, No Units Fee: Final Score: / Problems Ion Formation Section 7.1 of your book. 1. How do positive ions and negative ions form? 2. Why are halogens and alkali metals likely to form ions? Explain your answer. 3. Give the number of valence electrons in an atom of each element. a. Cesium d. Fluorine b. Rubidium e. Strontium c. Gallium f. Oxygen 4. Explain why noble gases are not likely to form chemical bonds. 5. Explain how an anion of nitrogen forms. 6. Explain how a cation of calcium forms. 70

3 6.2 Problems Ionic Bonds Section 7.2 of your book. Possible 6.2 Pts.: 8 Late, Incomplete, No work, No Units Fee: Final Score: / 8 1. What does the term electrically neutral mean when discussing ionic compounds? 2. How do ionic bonds form? In other words, what has to happen for an ionic bond to occur? In problems 3 6, determine the formula of each compound: 3. Potassium chloride, a salt substitute 4. Sodium fluoride, used in toothpaste 5. Calcium oxide, used to remove sulfur dioxide from power-plant exhaust 6. Strontium chloride, used in fireworks 7. Which compounds are not likely to occur: CaK, Na 2 S, BaCl 3, MgF? Justify your choices. 8. Which has the greater lattice energy, CsCl or KCl? K 2 O or CaO? Justify your choices. 71

4 Possible 6.3 Pts.: 5 Late, Incomplete, No work, No Units Fee: Final Score: / Problems Names of Ionic Compounds Section 7.3 of your book. 1. When are subscripts used in formulas for ionic compounds? 2. Explain what the name scandium (III) oxide means in terms of electrons lost and gained, and write the balanced formula for that compound. 3. Write the formula for each ionic compound. a. calcium iodide c. potassium periodate b. copper (II) chloride d. silver acetate 4. Name each of the following ionic compounds. a. CuBr 2 d. NaClO b. CaCl 2 e. Pb(SO 4 ) 2 c. Mg 3 N 2 f. KNO 3 5. There are errors in the following formulas - write the correct formulas. a. AlCl c. BaOH 2 b. Na 3 SO 4 d. Fe 2 O 72

5 1. Describe a metallic bond. 6.4 Problems Metallic Bonds Section 7.4 of your book. Possible 6.4 Pts.: 5 Late, Incomplete, No work, No Units Fee: Final Score: / 5 2. Briefly describe how malleability and ductility of metals are explained by metallic bonding. 3. Copper and zinc are used to form brass, an alloy. Briefly explain why these two metals form a substitutional alloy and not an interstitial alloy. 4. The melting point of beryllium is 1287 degrees Celsius, while that of lithium is 180 degrees Celsius. Explain the large difference in values. 5. Titanium (maximum charge: +4) has a boiling point of 3287 degrees Celsius, and copper (maximum charge: +2) has a boiling point of 2567 degrees Celsius. Explain why there is a difference in the boiling point of these two metals. 73

6 Chemistry Name: Lab Points: Missed: Late, No Units, No Work Fee: Lab - Build Your Own Ionic Solid! First Score: Corrections: Correction Credit: Half Final Score: Theory: Ionic compounds are substances made of equal numbers of positive and negative charges. In this lab common household substances vinegar and baking soda - will react to make one ionic and two molecular compounds according to the reaction: HC 2 H 3 O 2 + NaHCO 3 NaC 2 H 3 O 2 + CO 2 + H 2 O Reactants Products Safety: You will be using Bunsen burners to heat up an acidic solution. Heat glassware slowly, and pay close attention when your solution gets close to the end of its boiling. Goggles, long pants, and close-toed shoes must be worn during the entire lab. Clean glassware is ESSENTIAL for this lab. Even if it already looks clean, wash out the glassware you intend to use before starting. Equipment and Chemicals: Ring Stand with Side Clamp Steel Mesh Balance and Weighing Boat Bunsen Burner and Striker 250 ml, 100 ml Beakers 10 ml, 100 ml Graduated Cylinders Small Test Tube and Clamp Tongs Glass Stirring Rod 2 ml Plastic Dropper Boiling Stones 5% Acetic Acid (Vinegar) Sodium Bicarbonate (Baking Soda) Procedure: Setup: 1. Obtain 3.0 grams of sodium bicarbonate using a pre-weighed boat. 2. Put the sodium bicarbonate into the 250 ml beaker. 3. I will deliver 50.0 ml of acetic acid into your graduated cylinder. Pour it into the 100 ml beaker. Note: you will not need all 50 ml of acid in the next part. Neutralization: 4. Slowly and gradually measure and add exactly 35 ml (with graduated cylinder) of acid to your 250 ml beaker of baking soda while stirring with the rod. The liquid will foam, so pour only a little at a time. As you are stirring, you should notice the baking soda dissolving until there is no powder remaining in your reaction beaker. 5. Gently heat (do not boil yet!) your beaker with the burner. It will foam more, so stir it with the glass rod until the bubbles diminish. 6. Using the 2 ml plastic dropper, drop acid slowly into your heated solution until you see that bubbles no longer form. 74

7 Concentration: 7. Pour 3 ml of deionized water into the small graduated cylinder for later. 8. Once the reaction bubbles have stopped, add 5 boiling stones and bring the solution to a boil, stirring it the whole time. 9. When the level of liquid gets down to the top of your boiling stones, you are getting close to the end of your operation. Pick up the 250 ml beaker with your tongs while swirling to heat it more slowly. 10. Swirl the solution until the bottom of the beaker SUDDENLY turns white and a layer of crystals forms. Turn off the heat as soon as this happens. 11. Immediately pour the 3 ml of deionized water onto the crystals and swirl the solution around, dissolving as much crystalline residue as possible. 12. Don t wait too long, and carefully pour the hot liquid into the small test tube, leaving the boiling stones in the beaker. 13. Cool the test tube by running it under cold water (don t get water in the tube!) until it is cold to the touch. 14. Tell me when it s cool, and I will come around to test whether you followed the directions correctly by placing a seed crystal in it. If it all crystallizes, then you ll get full credit for the procedure! Clean up: Bring your test tubes with sodium acetate to me and I will recover and use it. Pour the boiling stones into the waste beaker and I will wash and reuse them. Wash the rest of your dishes and put them away. Questions: Answer in complete sentences. 1. (2 pts) Define polyatomic ion. You may have to use your book. 2. (3 pts) Name the three products of the reaction (see the reaction in the Theory section. You will have to use your Table of Ions Resource too). 3. (2 pts) Which of the three products has a metal and a polyatomic ion? 4. (3 pts) Describe what happens when a seed crystal is added. What happens to the temperature of the solution? Write this in at least three complete sentences for full credit. 75

8 Chemistry Name: Essential Skill - Ionic Compounds Part 1 Period: This is a practice worksheet to prepare you in the short term for the Ionic Compounds Quiz, and for the long term by reinforcing an essential skill in chemistry. Part 1. Use your rules of naming ionic compounds and table of common ions to write out the formulas of the following compounds: 1. calcium bromide 2. silver phosphate 3. cobalt (II) nitrate 4. copper (I) arsenate 5. nickel cyanide 6. hydrogen peroxide 7. iron (III) oxide Part 2. Name the following compounds. Don t forget Roman numerals for the metals with more than one oxidation state! 8. FeO 9. Cd(ClO 3 ) Al(NO 3 ) KMnO Cu(OH) Sr(ClO 4 ) Co 2 (HPO 4 ) 3 76

9 Ion Game: 5 Points for playing Objective: Your lab group s objective is to get as many points as possible by forming and naming chemical compounds. Rules: 1. Each group gets a set of one positive and one negative ion cards. 2. Groups then have three minutes to determine the irreducible balanced chemical formula and name with the ions they have. You can duplicate ions you ve been given if you need more than one to make a balanced formula. 3. After three minutes, teams will write the formulas and names of their compounds legibly on the board. 4. If a chemical formula or name is incorrect, a randomly selected team can challenge it and provide a correct formula or name. 5. If no one challenges a false answer, then I will challenge it. Scoring: 1. Teams earn one point for each correct formula/name pair. 2. Teams earn one point for challenging and correcting a formula or name from another team. 3. Teams that were challenged unsuccessfully earn a point. 4. All other teams lose a point if I challenge an incorrect formula or name. 77

10 Chemistry Name: Essential Skill - Ionic Compounds Part 2 Period: This is a practice worksheet to prepare you in the short term for the Ionic Compounds Quiz, and for the long term by reinforcing an essential skill in chemistry. Part 1. Write the formulas of the following compounds: 1. ammonium oxalate 2. zinc bicarbonate 3. magnesium nitride 4. lithium sulfate 5. aluminum iodide 6. tin (IV) dichromate 7. sodium chromate 8. lead (II) fluoride Part 2. Name the following compounds. Include Roman numerals where needed. 9. (NH 4 ) 2 CO CaCl Pb(CrO 4 ) ZnS 13. BaI Be(C 2 H 3 O 2 ) Li 2 SO NaHCO 3 78

11 Points Possible: 10 Unit 6 Review Ionic Compounds Late/Inc. Fee: This serves as test preparation for the Unit 6 exam. Points earned are Final Score: / 10 based on completion, and we will go over any questions you have during the review. Additionally, you may be called upon to present a selection of these problems to the class. Write formulas for the following: 1. tin (IV) chloride 2. zinc phosphate 3. lithium sulfate 4. aluminum oxide 5. aluminum cyanide 6. hydrogen sulfide 7. calcium oxide 8. iron (III) sulfate 9. magnesium bicarbonate 10. potassium sulfate 11. aluminum iodide 12. zinc carbonate Name the following compounds. 13. CaBr FeCl CuS 16. Ba(NO 3 ) Cu 2 Se 18. Na 3 PO Cu(OH) K 2 S 21. LiClO MgF Ni(CN) K 2 SO List and define four properties of metals. 26. What are delocalized electrons? 27. Rank the following in order of increasing lattice energy: NaCl, KCl, LiF, LiCl, KBr. 28. Draw an electron dot structure of atomic oxygen, and the oxide ion. 29. Define interstitial alloy, and identify one. 79

12 30. Define substitutional alloy, and identify one. 31. What is a chemical bond? 32. Which elements form anions? 33. Why do ionic compounds shatter when hit, but metals bend? 34. How are monatomic ions different from polyatomic ions? 35. What are the charges of cations and anions? 36. Do nonmetals lose or gain electrons to become ions? 37. Name two metals that have multiple oxidation numbers (charges), and what they are. 38. Draw a metal lattice using aluminum atoms show bonds that form between the metal centers and the delocalized valence electrons. 80