Chemistry 111 Exam 2: Part 3; 5.1-5.2

Electron-Pair Repulsion Theory

What theory explains that the electron pairs that exist create repulsion for each other, and will be as far apart as possible surrounding an atom?

Lewis structure

What shows you how atoms are connected by electron placement?

ball-and-stick model

What shows you the actual shape and bond angles of a molecule?

the molecular formula

What tells you only which elements are in a molecule?

repel

Valence shell electron pairs _____________ each other

tetrahedral; triagonal pyramidal, >109.5°

In NH₃, there are 3 bonding pairs (ligands) and one lone pair. What is the electron group geometry, molecular shape and bonding angle of this molecule?

electron domain

What is a lone pair of electrons, or a bond (single, double or triple), in the valence shell around an atom?

steric number

What is the total number of electron domains surround an atom referred t?

electron-group geometry

_______________ is the 3-D arrangement of the valence shell electron domains (lone pains and atoms)

molecular geometry

___________________ describes the actual 3-D arrangement of the atoms surrounding the central atom

2; linear; linear; 180°

A C0₂ molecule has the steric number of ___, electron group geometry of _________ molecular geometry that is__________ and bond angle of _____

3; trigonal planar; trigonal planar; 120°

BF₃ has a steric number of ______, _________ electron group geometry, _________ molecular geometry and a bond angle of________

4; tetrahedral; tetrahedral; 109.5°

CCl₄ has a steric number of ______, ________electron group geometry, _________ molecular geometry, and a bond angle of ______

5; trigonal bypiramidal; 90° and 120°

What is the steric number, molecular shape, and bond angle(s) for PF₅?

6; octahedral; 90°

What is the steric number, molecular shape and bond angle for the molecule SF₆?

Draw the Lewis structure

What is the first step when determining molecular shape?

Find the steric number for any inner atom

What is the second step in determining molecular shape?

determine the electron group geometry around each inner atom from the steric number

What s the third step when determining molecular shape?

determine ligands versus lone pairs within an electron-group geometry

What is the final step when determining molecular shape?

4; tetrahedral; bent; 109.5

What is the steric number, electron-group geometry, molecular shape and bond angle(s) of H₂O?

5; trigonal bipyramidal; see-saw; <90° and <120°

What is the steric number, EEG; molecular geometry and bond angle(s) for SF₄?

5; trigonal bipyramidal; T-shaped; <90°

What is the steric number, EEG, molecular geometry and bond angle(s) for ClF₃?

5; trigonal bipyramidal; linear; 180°

What is the steric number, EEG, molecular shape, and bond angle(s) of a molecule where the central atom has 2 ligands and 3 lone pairs?

6; octahedral; octahedral; 90°

What is the steric number, EEG, molecular shape, and bond angle(s) of the molecule SF₆?

6; octahedral; square pyramidal; 90° and <90°

What is the steric number, EEG, molecular shape, and bond angle(s) ClF₅?

6; octahedral; square planar; 90°

What is the steric number, EEG, molecular shape, and bond angle(s) of the molecule XeF₄?

-1; 2

What is the formal charge of one of the oxygens on the structure NO₂⁻? How many resonance structures are there?

1.5 or 3/2

What is the bond order of NO⁻?

lone pairs

What has greater electron repulsion than any single, double or triple bond?

triple bonds; double bonds; single bonds

List the order of electron repulsion from highest to lowest in bonds:

1.3 or 4/3

What is the actual bond order of the nitrate ion?

low

Meals have very ______ electronegativity compared to nonmetals

share; covalent

nonmetals have similar electronegativity to each other so tend to ________ elcetrons as ______ bonds