You have spend hours working on your research paper, much like you will in college. And just like in college, you need to give a presentation over your research, a defense as it is commonly called. These presentations will be the focus of the last 2 weeks PDF

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You have spend hours working on your research paper, much like you will in college. And just like in college, you need to give a presentation over your research, a defense as it is commonly called. These presentations will be the focus of the last 2 weeks of class. Because you should already extens...

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Logout (https://myhol.holscience.com/logout) EXPERIMENTATION   – 1150 Introduction to General   CHMEXPLORATION EVALUATION  Chemistry

Molecular Modeling and Lewis Structures Final Report

Student Name

Charlotte Grumbles

Student ID

42836

Lesson

Molecular Modeling and Lewis Structures



Institution

Clark State Community College

Session

Spring 2019

Course

CHM – 1150 Introduction to General Chemistry

Instructor

Cherish Lesko

Closely review your work. You will NOT be able to change your answers in the experimentation section once you click “Submit Your Data” below. This Final Report page displays the answers and data you recorded throughout the lesson. Review the entire page to ensure your work is accurate and nothing is missing. To finalize the report, click “Submit Your Data” below. Turn in the Final Report using your instructor’s preferred method.

Test Your Knowledge

1. Match the number of valence electrons with the correct compound.

CH4

1

8

2

PBr 3

2

26

2

OF 2

3

20

2

CH2O

4

12

2

O3

5

18

2

SiCl4

6

32

2

2. Move the terms to complete each statement.

A model that describes the three dimensional arrangement of electrons based on electron repulsion is called the 1

2 model.

VSEPR

Two hydrogen atoms form a 2

duet

2

when they have covalent bonds.

Diamond and graphite are two 3

allotropes

2 of

carbon.

Resonance

4

structures

2 show the same

connection of atoms but different arrangement of the bonds.

An atom that has less than eight electrons surrounding it in a compound is said to be 5

electron deficient 2 .

The number of outermost electrons is the number of 6

valence electrons 2 .

3. Determine the correct molecular geometry based on the number of bonds and lone pairs around the central atom.

Bonds

Lone Pairs

Geometry

2

2

1

Bent

2

3

0

2

Trigonal Planar

2

3

1

3

Trigonal Pyramidal 2

4

0

4

Tetrahedral

2

Exploration

1. The localized electron model assumes that a molecule is bonded through the _____. sharing of valence electron pairs transfer of valence electron pairs



FEEDBACK Awesome!

2

2. Allotropes are _____. different structural modifications of an element

2

versions of an element having the same number of neutrons but differing numbers of protons molecules bonded through the sharing of valence electron pairs typically crystalline in structure



FEEDBACK Great!

3. The number of valence electrons of an atom can be found in the row number on the periodic table. True

1

False

2



FEEDBACK This statement is false.The number of valence electrons of an atom can be found in the groupnumber on the periodic table.

4. Magnesium has _____ valence electrons. 1 2

2

3 4 8

FEEDBACK Excellent!

5. An example of an atom with 3 valence electrons is _____. sodium magnesium aluminum

2

All of the above

1



FEEDBACK An example of an atom with 3 valence electrons is aluminum.

6. The octet rule is based upon the observation that atoms are most stable when surrounded by how many valence electrons? 6 4 12 2

8



FEEDBACK Well done!

7. Resonance occurs when there is only one option for the Lewis structure model. True False

2

FEEDBACK Exactly! Resonance occurs when there is morethanoneoption for the Lewis structure model.

8. What atoms always obey the octet rule? Hydrogen, carbon, nitrogen, oxygen Nitrogen, oxygen, fluorine, copper Oxygen, fluorine, nitrogen, carbon

2

Oxygen, carbon, chlorine, helium



FEEDBACK Nicely done!

9. The goal of the VSEPR model is to arrange the position of the atoms and lone pairs surrounding the central atom in a manner that minimizes _____. lone pairs the number of electrons repulsion space and size



FEEDBACK Very good!

2

10. Molecular modeling kits are useful in determining the Lewis structure of a molecule. True

1

False

2



FEEDBACK This statement is false.Molecular modeling kits are used to visualize the three-dimensionalstructure of a molecule. Lewis structures are two-dimensional.

11. When a molecule has more than one interior atom, _____. multiple Lewis structures may be drawn the atoms are always represented by different colored balls in the modeling kit more than one geometry may be used to describe the molecule the atoms are always connected by a double bond



FEEDBACK Terrific!

2

Exercise 1 Data Table 1: CHO2-

# of Valence Electrons

# of Atoms or Sets of Lone Pairs Surrounding Central Atom

Structure Geometry (Name)

18

There is only one central (or interior) atom in this molecule. The carbon atom in the middle is the central atom- it is surrounded by two oxygen atoms and one hydrogen atom. Carbon is surrounded by a total of three bonds: 1 double bond + 2 single bonds. A double bond contains 4 electrons; a single bond contains 2 electrons. There are no lone pairs around the carbon atom.

Trigonal planar

Photo 1: Lewis Structure of CHO2-

Photo 2: VSEPR Model of CHO2-

Exercise 2

1. Which, if any, of the substances had resonance structures? How many resonance structures did each substance have? NO2- has resonance structure..it has two resonance structures possible... O==N---O- -O---N==O

2. Both chlorine and fluorine are represented by a green modeling piece that has 4 holes. Is using the same piece for two different atoms acceptable? Why or why not? Yes, the fall within the same group of 7A.

3. Explain why only the lone pairs on the central atom are taken into consideration when predicting molecular shape. What substances from the lab activity have more than one central atom? For lone pair only distortion happens from ideal geometry and the name is VSEPR that is valence shell electron pair repulsion theory so based on the repulsion these structures are determined..if none of lone pairs change then repulsion also varies and deviation occurs from ideal structure. If more than one central atom present that is the case of H2O2 no problem arises...it is also planar in shape

Data Table 2: VSEPR Names and Atoms

Molecule or # of Valence Ion Electrons

# of atoms or sets of lone pairs Structure surrounding central atom Geometry (Name)

CCl4

32

4

tetrahedral

H2 O

8

4

tetrahedral

CO2

16

2

linear

H2 O2

14

4

tetrahedral

CH4

8

4

tetrahedral

C2 H4

12

4

tetrahedral

CH2O

12

3

trigonal planar

CH3OH

14

4

tetrahedral

CH3NH2

14

4

tetrahedral

NF3

26

4

tetrahedral

NH3

8

4

tetrahedral

[NH4 ]+

8

4

tetrahedral

[NO2 ]-

18

3

trigonal planar

SO2

18

3

trigonal planar

OF2

20

4

tetrahedral

H2 S

8

4

tetrahedral

SF6

48

6

Octahedral

ICl5

42

6

Octahedral

Photo 3: CCl4 Lewis Structure and VSEPR Model

Photo 4: H2 O Lewis Structure and VSEPR Model

Photo 5: CO2 Lewis Structure and VSEPR Model

Photo 6: H2 O2 Lewis Structure and VSEPR Model

Photo 7: CH 4 Lewis Structure and VSEPR Model

Photo 8: C2 H4 Lewis Structure and VSEPR Model

Photo 9: CH 2O Lewis Structure and VSEPR Model

Photo 10: CH3OH Lewis Structure and VSEPR Model

Photo 11: CH3NH2 Lewis Structure and VSEPR Model

Photo 12: NF3 Lewis Structure and VSEPR Model

Photo 13: NH3 Lewis Structure and VSEPR Model

Photo 14: [NH4 ]+ Lewis Structure and VSEPR Model

Photo 15: [NO2 ]- Lewis Structure and VSEPR Model

Photo 16: SO2 Lewis Structure and VSEPR Model

Photo 17: OF2 Lewis Structure and VSEPR Model

Photo 18: H2 S Lewis Structure and VSEPR Model

Photo 19: SF6 Lewis Structure and VSEPR Model

Photo 20: ICl5 Lewis Structure and VSEPR Model

Competency Review

1. Different structural modifications of an element are called _____. allotropes valences pairs octets



FEEDBACK This question focuses on Learning Objective 1: Define allotropes, valence electrons, and lone pairs.

2

2. Valence electrons include all electrons of an atom. True False



2

FEEDBACK valence electrons include those in the outershell. This question focuses on Learning Objective 1: Define allotropes, valence electrons, and lone pairs.

3. Valence electrons that are not shared between two atoms are called _____. doublets lone pairs

2

octets electron deficient



FEEDBACK This question focuses on Learning Objective 1: Define allotropes, valence electrons, and lone pairs.

4. The duet rule is based upon the observation that atoms are most stable when surrounded by eight valence electrons. True False

FEEDBACK The octet rule is based upon the observation that atoms are most stable when surrounded by eight valence electrons.

2

This questions focuses on Learning Objective 2: Describe the duet rule and octet rule.

5. The _____ of a molecule visually describes the two-dimensional arrangement of atoms and valence electrons in a molecule. localized electron model charges Lewis structure



2

FEEDBACK This question focuses on Learning Objective 3: Define and create Lewis structures.

6. The first step in creating a Lewis structure is to determine the total number of valence electrons for the entire molecule. True

2

False



FEEDBACK This question focuses on Learning Objective 3: Define and create Lewis structures.

7. The valence shell electron pair repulsion (VSEPR) model _____. describes the three-dimensional arrangement of the atoms in a molecule 2 states that two negatively charged particles (electrons) will always repel one another with equal and opposite forces ensures bonding through shared valence electron pairs is the illustrated definition of the octet rule but not the duet rule



FEEDBACK This question focuses on Learning Objective 4: Describe the valence shell electron pair repulsion (VSEPR) model.

8. In a molecular modeling kit, a black ball with 4 holes most likely represents the element _____. hydrogen carbon

2

magnesium sulfur



FEEDBACK This question focuses on Learning Objective 6: Create VSEPR models of molecules with molecular modeling kits.

9. The Lewis structure for H2 O includes double bonds. True False



2

FEEDBACK H 2O only has single bonds. This question focuses on Learning Objective 5: Draw Lewis structures for molecules.

10. Some compounds have more than one Lewis structure. True False

2

FEEDBACK This question focuses on Learning Objective 8: Diagram resonance structures.

11. Alkali metals are a group located at the far left of the periodic table; alkali metals have _____ valence electron(s). 2

1 2 6 7



FEEDBACK This question focuses on Learning Objective 7: Identify the number of valence electrons of elements using the periodic table.

12. Carbon dioxide has a _____ geometric structure. tetrahedral octahedral trigonal planar linear



2

FEEDBACK This question focuses on Learning Objective 9: Classify the VSEPR model of a molecule as: linear, tetrahedral, trigonal planar, bipyramidal, or octahedral.

13. SF6 has a _____ geometric structure. tetrahedral octahedral

2

trigonal planar linear



FEEDBACK This question focuses on Learning Objective 9: Classify the VSEPR model of a molecule as: liner, tetrahedral, trigonal planar, bipyramidal, or octahedral.

Extension Questions

1. For each molecular shape, identify the number of bonds around the central atom and the number of lone pairs around the central atom.

0

2

0

3

0

4

0

3

1

2

2

5

0

6

5

0

1

()...