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This document is not meant to be a subsƟtute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s quesƟons, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ wriƟng of lab reports by providing this informaƟon in an editable file which can be sent to an instructor.

OBSERVATIONS

Part A: PRACTICE EXAMPLES
Count Valence e-	Formula	Electron Geometry	Molecular Geometry
1 N = 5 3 H = 3 8 / 2 = 4 pair	NH3	Tetrahedral	Trigonal pyramidal
	H2O
	CBr4
	SO3 This is not a polyatomic ion … No charge!!!
	PI3
	CH3Cl Carbon is the central atom
	NO 1- 3
	CO 2- 3
	NH +1 4
	CH4
	SO2

Experiment

LEWIS STRUCTURE MODEL

10

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For the following compounds, there is more than 1 central atom. Count the total number of valence electrons, divide by 2. Draw the Lewis Structures: share the electron pairs around each atom to complete the bonding. Recall that double and triple bonds may be necessary. Determine the structure on each of the central atoms.

Part B: PRACTICE EXAMPLES
Count Valence E	Formula	Structure	Molecular Geometry
1 C = 4 3 H = 3 1 O = 6 1 H = 1 14 e/2 =7 pair	CH3OH	electron geometry C – tetrahedral O – tetrahedral	C = tetrahedral O = bent 2 bonded 2 non bonded
	CH3NH2
	CH2CH2 Looks like H2C - CH2 Hint ; double bond
	CH3OCH3 Looks like H3C – O – CH3