10-09 SI Session

Electron Domain Geometry

100

What is the electron domain geometry of NO₂^-_.

Trigonal planar

200

1. What is the electron domain geometry of SF₄?

2. What is the electron domain geometry of BrF₅?

1. Trigonal Bipyramidal

2. Octahedral

300

What is the Electron Domain geometry of these molecules?

1. H₂S

2. SnCl₂

1. Tetrahedral

2. Trigonal planar

400

What is the electron domain geometry of the following molecules?

1. BF₃

2. PCl₅

3. O₃

1. Trigonal Planar

2. Trigonal Bipyamidal

3. Trigonal Planar

500

 

What is the ideal bond angle on the two nitrogens in this structure?

Answer: 120 degrees

Remember: Atoms need to have a full octet unless they are explicitly stated to have a + or - charge. This image can be confusing because it does not draw in lone pairs. On both nitrogen atoms there is a lone pair, meaning there are three electron domains. 

Ideal bond angle = Electron Domain Geometry angle

Polar vs Nonpolar

100

1. If a molecule has a lone pair on its central atom, is it likely polar or nonpolar?

2. If a molecule has symmetric arrangement of terminal atoms, is it likely polar or nonpolar?

1. polar

2. nonpolar

200

1. CO2 -- polar or nonpolar? why? Is the BOND between C and O polar or nonpolar? 

- CO2 as a molecule is nonpolar because it has no lone pairs on central atom and has symmetric arrangement of terminal atoms

- Bond between C and O is polar, C and O have different electronegativities

300

Is the molecule BF3 polar or nonpolar?

Nonpolar! No lone pairs on central atom, symmetry (X and Y forces cancel)

400

Are these molecules polar or nonpolar:

1. SO2

2. SF6

1. Polar

2. Nonpolar

500

Are these molecules polar or nonpolar?

1. CCl₄

2. H₂

3. XeF₄

1. Nonpolar

2. Nonpolar

3. Polar

Molecular Geometry

100

What is the molecular geometry of this molecule:

Seesaw

200

What are the molecular geometry of these molecules:

1. SF₄

2. BrF₅

1. Seesaw

2. Square Pyramidal

300

What is the molecular geometry of the following compounds:

1. H₂S

2. SnCl₂

1. Bent

2. Bent

400

What is the molecular geometry of the following molecules:

1. BF₃

2. PCl₅

3. O₃

1. Trigonal Planar

2. Trigonal Bipyramidal

3. Bent

500

FREE SPACE!! Team that picks gets a bonus 500 points :)

YAY!

Conceptual

100

What molecular shapes are ALWAYS polar from the following options, even when bonds are equivalent (select all that apply):

a. bent

b. tetrahedral

c. seesaw

d. square planar

a and c

- square planar is the weird one that you just need to remember is nonpolar if all bonds are equivalent

200

If a molecule is polar, does it have a higher or lower boiling point than a molecule that is nonpolar?

Polar --> polar molecules attract each other through partial charges (dipoles)

300

Rank the following in order of increasing repulsivity:

A. single bond

B. triple bond

C. double bond

D. lone pair

A, C, B, D

400

Pictured below are structural isomers of a molecule. Which isomer is polar and which is nonpolar? Why?

Top = Non-polar because dipoles cancel out

Bottom = Polar because the dipoles do not cancel out.

500

Rank the following in order of decreasing bond angle deviation assuming that each molecule has the same number of single, double, and triple bonds:

1. Seesaw

2. Trigonal Bipyramidal

3. T-shaped

T-shaped > Seesaw > Trigonal Bipyramidal

- more lone pairs = more repulsion = greater bond angle deviation 

IMFs

100

Select all of the following that are properties of water due to hydrogen bonding:

A. Ice Floats

B. Low Boiling Point

C. High Surface Tension

D. Cohesion and Adhesion

A, C, D

(water has high boiling point due to h bonding)

200

Rank the following types of bonds in terms of INCREASING strength:

Hydrogen Bond

Ionic Bond

London Dispersion Force

Dipole-Dipole

Dispersion Force < Dipole - Dipole < Hydrogen Bond < Ionic Bond

300

Rank the following bonds in terms of low to high boiling point:

A. Hydrogen Bond

B. Dispersion Force

C. Dipole-Dipole

B < C < D

400

Rank the following molecules in terms of increasing boiling point:

CH₄OH, NaCl, C₃H₆, CH₄Cl

C₃H₆, CH₄Cl, CH₄OH, NaCl

500

What types of molecules form the following bonds:

A. Dipole-Dipole

B. Hydrogen Bonds

C. Ionic Bonds

D. London Dispersion Forces

A. Polar molecules only

B. H with F,O,N

C. Metal and Nonmetal

D. ALL MOLECULES