Chem 1211 1st Edition Lecture 21Outline of Last Lecture I. Atomic Properties, ContinuedII. Chapter 8 IntroductionOutline of Current Lecture I. Lewis Dot StructuresCurrent LectureI. Lewis Electron Dot Structuresa. Moleculesi. Diatomic with the same atoms (H-H, of F-F)ii. Diatomic with different atoms (ex. H-Cl)iii. Polyatomic: water, H20, and ammonia, NH3iv. Pair electrons= a line= a bond b. ConcepTest: How many electrons appear in the correct Lewis dot structure for NH4+?i. 5ii. 6iii. 7iv. 81. ANSWER: 8 2. REASOING: Nitrogen has 5 electrons, and each hydrogen has 1 electron (for a total of 9). However, since there is a positive charge, that means there is one less electron than normalc. ConcepTest: How many lone pair electrons, single bonds, double bonds, and triple bonds, respectively, appear in the Lewis structure of HCN?i. 0, 1, 0,1ii. 2, 1, 0, 1iii. 0, 1, 1, 0iv. 2, 1, 1, Ov. None of these1. ANSWER: B: 2, 1, 0, 1These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.2. REASONING: Lewis structure is H-C---N:a. Carbon needs the most electrons, so it is in the middle. There is a single bond between Hydrogen and Carbon and a triple bond between Carbon and Nitrogen. There are twolone electrons.d. Valence e- for each elementi. Anion- add 1 e-ii. Cation- subtract 1 e-e. Central atom- atom that needs the largest number of e- to complete octeti. For atoms in the same group, the less electronegative; never Hf. Rulesi. Formal charge= group # - (# bonds + # unshared e-)1. Group # = valence e- in uncombined atom2. # bonds = ½ # bonding e-3. # unshared e- = # lone pair electronsg. ConcepTest: What are the formal charges for all the atoms in OCS in this structure? ::O=C=S::i. 0, 0, 0ii. 0, 1, 0iii. 0, 1, 1iv. 1, 1, 1v. None of these1. ANSWER: 0, 0, 02. REASONING: Following the formula for formal charges… a. Oxygen= 6 - (2+4)=0b. Carbon= 4 - (4+0)=0c. Sulfur= 6 - (2+4)= 0h. ConcepTest: How many lone pair electrons on the central atom, single bonds, double bonds, and triple bonds, respectively, appear in the Lewis structure of PF6-?i. 0, 3, 3, 0ii. 0, 6, 0, 0iii. 1, 3, 3, 0iv. 1, 6, 0, 0 v. 2, 6, 0, 01. ANSWER: 0, 6, 0, 0 2. REASONING: Phosphorus forms a single bond with each of the 6 fluorinesa. 3rd Row: Si, P, S, Cl can have more than 8 electrons (ex. 10, 12)i. Octet Rule Exceptions i. Electron count- stable noble gas electron configurations1. “octet rule” for most elements2. 2 for H3. 6 for Group 3A (B and
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