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    • C 3 – rotation by 120 o
    • C 4 – rotation by 90 o
    • C (infinity rotation axis) – rotation of any amount will result in an indistinguishable orientation
  • Does the molecule have an inversion center (i) ?

Determine which of these symmetry elements are present in your assigned molecules. All of the columns of the table on the report form should be filled out. If you have any difficulty determining whether such symmetry elements are present in the molecules you are assigned, your TA can provide examples of each symmetry element.

Extra credit points can be earned by indicating in the table how many of each symmetry element are present for each molecule (i.e. How many mirror planes are present?).

  2. Mirror Images

Using the model kits, build models which are the mirror images of the models you were assigned to build (b, c, d, e, f, g, h, i and j) in Part 1. With the two mirror images in hand, try to place the models on top of one another, atom for atom.

If you can do this, the model and its mirror image are superimposable mirror images of one another. If not, the molecule and its mirror image form nonsuperimposable mirror images. Nonsuperimposable mirror images are also known as enantiomers .

For each compound, decide whether the mirror image is superimposable or nonsuperimposable. Can you make a generalization about when to expect molecules to have nonsuperimposable mirror images?

  3. Isomers

In this exercise you will build models of compounds which are structural and/or geometrical isomers of one another.

Make the following models:

A. Structural Isomers

  1. Make a model(s) of C 2 H 5 Cl. How many different structural isomers are possible?
  2. Make a model(s) of C 3 H 7 Cl. How many different structural isomers are possible?
  3. Make a model(s) of C 3 H 6 Cl 2 . How many different structural isomers are possible?

 B. Geometrical Isomers

  1. Make a model(s) of C 2 H 3 Cl. How many different structural and geometrical isomers are possible?
  2. Make a model(s) of C 2 H 2 Cl 2 . How many different structural and geometrical isomers are possible?
  3. Make a model(s) of cyclobutane (C 4 H 8 ). HINT : cyclo = ring of C atoms
  4. Now make dichlorocyclobutane (C 4 H 6 Cl 2 ) by replacing two H atoms on cyclopropane with Cl atoms. How many different structural and geometrical isomers are possible for dichlorocyclobutane? You may wish to make a couple of cyclobutane molecules so that you can compare the structures. Do any of the isomers have nonsuperimposable mirror images?

C. Aromatic Ring Compounds

  1. Make a model of benzene, C 6 H 6 . Even though your model will contain alternating double and single bonds, remember that in the real molecules of benzene all the C-C bonds are equivalent. What symmetry elements does benzene possess?
  2. Make a model(s) of chlorobenzene, C 6 H 5 Cl. How many different structural and geometrical isomers are possible?
  3. Make a model(s) of dichlorobenzene, C 6 H 4 Cl 2 . How many different structural and geometrical isomers are possible?
  4. Make a model(s) of trichlorobenzene, C 6 H 3 Cl 3 . How many different structural and geometrical isomers are possible?

4. Hypervalent Structures

Hypervalent compounds are those that have more than an octet of electrons around them. Such compounds are formed commonly with the heavier main group elements such as Si, Ge, Sn, Pb, P, As, Sb, Bi, S, Se, Te, etc. but rarely with C, N or O. Refer to the rules for Electron Domain theory in order to assign Lewis structures to the following molecules. Describe possible isomeric forms and the bond angles between the atoms. How many lone pairs of electrons are present on the central atom of each molecule, if any? (** Your book will be very useful in aiding you with these structures **)

  1. PF 5
  2. PF 3 Cl 2
  3. SF 4
  4. XeF 2
  5. BrF 3

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Honors chemistry lab fall. OpenStax CNX. Nov 15, 2007 Download for free at http://cnx.org/content/col10456/1.16
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