520 likes | 669 Vues
This lesson focuses on the concepts of ionic and covalent compounds, including their naming conventions and formulas. You'll review chapters 1 and 2, tackling quizzes on ions, atomic structure, and practice questions for writing chemical formulas. Key topics include identifying the number of protons and electrons in ions, understanding the octet rule, and naming cations and anions. We will also explore how to convert between names and formulas for various compounds and practice with common ions and their corresponding formulas in preparation for upcoming quizzes.
E N D
13 September 2011 • Objective: You will be able to: • review chapter 2 concepts • Homework Quiz: • Give the number of protons and electrons in the ion Mg2+ • Name the compound BaCl2 • Write the formula for iodine heptachloride
Agenda • Homework Quiz • Ch. 1 #105 • Chapter 2 Review • Problems in Chapter 2? Homework: Chapter 1 Problem Set: Thurs.
Announcement • Do I have your signed syllabus page yet? • You really want to be a TA for chemistry…
Atoms, Molecules and Ions • Review your notes from 2.1 – 2.5
Ionization • A review of how to determine which ion an atom makes
Valence Shell • Valence Shell: The most outer energy level. • 1s22s22p63s23p3 1s 2s 2p 3s 3p
Stability 1s 2s 2p 3s 3p 1s 2s 2p 3s 3p
Valence Electrons: Label on your PTE 1 8 2 3 4 5 6 7
Group 1 s p s p New valence shell
Ions • Ion: An atom that has lost or gained one or more electrons • Cation: An atom that has lost an electron • Positive Charge • Anion: An atom that has gained an electron • Negative Charge
Octet Rule • Octet Rule: All atoms lose and gain electrons to form a full valence shell • H, He = 2 • All other elements = 8
Ions formed by group - Add to your PTE 1+ 1 8 2 2+ 3+ 3 4 5 3- 6 2- 7 1- Gain e- Lose e- Anions Cations
Number of Valence Electrons Li Be B F O N Cl P K Ca Al Se Br Kr
Anion or Cation? • Cation is positive because it has LOST electrons. • It is a positive thing to have a cat, and it would be sad if you lost your cat. • Anion is negative because it has GAINED electrons • Mnemonic?
Symbols for Ions • Element SymbolCharge • Li+ • Cl- • Al3+ • Number, then + or – • No need to write a “1” • 1 is often invisible in chemistry
Names for Ions • Cations: Same name as the element • Li+: lithium ion • Sr2+: strontium ion
Naming Ions • Anions: Ending changes to “-ide” • N3-: nitride ion • O2-: oxide ion • F-: fluoride ion • S2-: sulfide ion • Cl-: chloride ion • Br-: bromide ion • I-: iodide ion
Polyatomic Ions NH4+ ammonium CO32- carbonate HCO3- hydrogen carbonate ClO3- chlorate CrO42- chromate Cr2O72- dichromate CN- cyanide PO43- phosphate HPO42- hydrogen phosphate H2PO4-dihydrogen phosphate
More Polyatomic Ions SO32- sulfite SO42- sulfate HSO4- hydrogen sulfate OH- hydroxide NO3- nitrate NO2- nitrite MnO4- permanganate O22- peroxide
14 September 2011 • Objective: You will be able to: • Name ionic and covalent compounds • Homework Quiz: • Write the formulas for: • iron (III) chloride • ammonium sulfate • dihydrogen monoxide
Agenda • Homework Quiz • Questions about ch. 1 problem set? • Chapter 2 review Homework: Ch. 1 problem set due tomorrow
Formulas of Ionic Compounds • Formed by electrostatic attraction between cations and anions. • Examples: • potassium bromide • zinc iodide • aluminum oxide • magnesium nitrate • iron (II) chloride (p. 54 for charges of transition metals)
Practice • rubidium sulfate • barium hydride • manganese (IV) oxide • ammonium carbonate
Names of Ionic Compounds • Examples • KBr • CuCl • FeCl3 • Cu(NO3)2 • KH2PO4 • NH4ClO3
Practice • MgBr2 • Li2SO3 • PbO • FeCO3
Molecular Compounds • Prefix system • 1 mono (**only used for second element in compound) • 2 di • 3 tri • 4 tetra • 5 penta • 6 hexa • 7 hepta • 8 octa • 9nona • 10 deca
Naming Molecular Compounds • Examples • CO • CO2 • N2O4
Practice Naming Molecular Compounds • SiCl4 • P4O10
Writing Formulas for Molecular Compounds • Examples • nitrogen dioxide • dihydrogen monoxide
Practice Writing Formulas for Molecular Compounds • nitrogen trihydride (a.k.a. ammonia) • carbon tetrachloride (a.k.a. freon) • carbon disulfide • disiliconhexabromide
Naming Acids • Acid: any substance that yields hydrogen ions (H+) when dissolved in water • If the anion ends in “-ide”, the acid is a “hydro –ic” acid HF hydrofluoric acid HCl hydrochloric acid HBrhydrobromic acid HI hydriodic acid HCN hydrocyanic acid H2S hydrosulfuric acid
Oxoacids • Contain hydrogen, oxygen and another element. • Used as reference acids to name other acids H2CO3 carbonic acid HClO3chloric acid HNO3 nitric acid H3PO4 phosphoric acid H2SO4 sulfuric acid
More oxoacids • Often, two or more oxoacids have the name central atom but a different number of O atoms • Adding one O atom to an “-ic” acid = “per… -ic” acid • Removing one O atom from an “-ic” acid = “-ous” acid • Removing two O atoms from an “-ic” acid = “hypo…-ous” acid
Oxyacid examples • HClO3chloric acid • Add an oxygen: HClO4 • perchloric acid • Remove an oxygen: HClO2 • chlorous acid • Remove two oxygens: HClO • hypochlorous acid
Oxyacid Problems • Name the following oxyacids • HNO2 • H2SO3 • H2CO4 • H2SO2
Naming Bases • A base yields hydroxide (OH-) ions when dissolved in water • NaOH sodium hydroxide • Ba(OH)2 barium hydroxide (Some bases don’t contain OH-, but more on that later.)
Hydrates • Hydrates are compounds with a specific number of water molecules attached to them • Example: CuSO4·5H2O • copper (II) sulfate pentahydrate • BaCl2·2H2O • barium chloride dihydrate
15 Sept. 2011 • Objective: You will be able to: • Practice identifying subatomic particles, isotopes, determining ionization, naming and writing formulas for compounds. • design a procedure to determine the formula of a hydrate.
Agenda • Questions about chapter 2 summer assignment? • Chapter 2 problem set • Design an procedure! Homework: Chapter 2 problem set: Tues. Ch. 1-2 quiz Tues.
Your challenge! • Copper (II) sulfate hydrate • Hydrate: a compound with water “tagged on to” the crystal structure. • Determine the number of molecules of water of hydration per formula unit of copper (II) sulfate.
Your procedure… • A complete list of steps which include • specific quantities • names of equipment you’ll need to use • some way to determine when your procedure is “finished” • Directions and equations for any calculations you’ll need to make Due: Monday!
Homework • Quiz on ch. 1-2 Tuesday • Lab procedure: Monday
19 September 2011 • Take out your lab notebook and turn to your procedure • Objective: You will be able to: • carry our your procedure and collect data to determine the number of molecules of water of hydration of copper (II) sulfate hydrate.
Agenda • Procedure discussion • Carry out your procedure • Make calculations Homework: Quiz on ch. 1-2 tomorrow Chapter 2 problem set: Tues. Complete calculations (including name of hydrate): Thurs.
Safety • Wear goggles until all your equipment has been cleaned and returned. • A hot crucible looks just like a cold crucible! Always use crucible tongs. • Work efficiently but carefully.
Technical notes • Heat the crucible uncovered or with the cover tilted to allow water vapor to escape. • Cool the crucible with the cover on. • Cool the crucible in the desiccator for very best results. • Never mass a hot or warm crucible. • Oil from your fingers will stick to the crucible and effect your data.
Work Ethic • Work quickly. If you have “down time,” think: “What can I do now to save time later?” • Set up data tables and calculations while you wait.