Chem 1211 1st Edition Lecture 23Outline of Last Lecture I. Octet RuleII. GeometryIII. ElectronegativityOutline of Current Lecture I. Geometry ContinuedII. Electronegativity continued Current LectureI. Geometry Continueda. ConcepTest: What are the electron-pair and molecular geometries for PCl5?i. Octahedron, trigonal bipyramidii. Trigonal bipyramid, tetrahedroniii. Tetrahedron, trigonal pyramidiv. Trigonal pyramid, bent v. None of these1. ANSWER: None of these.2. REASONING: P has 5 single bonds, and no lone electron pairs. It is trigonal pyramid, but not bentb. Which pair of atoms would be predicted to have an ionic bond based on electronegativity values? i. N, Clii. P, Cliii. N, Fiv. Cl, Na1. ANSWER: Cl, NaII. Electronegativity a. Bondsi. Equal sharing (electronegativity <.5)These 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.ii. Polar covalent (electronegativity = .7-1.8)iii. Ionic (electronegativity > 2) b. Opposite charges attractc. Fluorine molecules (4.0 electronegativity) will float around randomly; they will not be pulled in a certain direction d. Measure Charge Separationi. Experiment (values)ii. Dipole moment- has two connected poles, one with a + charge and one with a – charge iii. Bigger dipole, bigger charge separation iv. Dipole moment (u)= charge x distancev. Look up in tablee. ConcepTest: Which molecule DOES NOT have a dipole moment?i. CH4ii. CH3Fiii. CH2F2iv. CHF3v. CF41. ANSWER: CH42. REASONING: The answer is not CF4 because fluorine makes it polar.f. Polar bonds: componentsg. Dipole moments: moleculari. BF3- planar, polar bonds pull with the same force in 3 different directions h. Using basic principles, which double bond would you expect to be the long, C=C, C=O, C=N?i. C=Cii. C=Oiii. C=N1. C=C, because C has the biggest radius (look at periodic table
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