Practicum Report_Hydrocarbon and its Derivative_GROUP 5_CESP 20

PRACTICUM GUIDE BOOK

Cis-Trans and E-Z Geometry Isomers for Alkena and Newman Projection Molecular
Model from Eclipsed, Staggered and Anti for The n-butane Molecule.

Arranged by GROUP 5:

Miranda A. Sihite (4203131031)
Mutiara Panca Putri Sinuhaji (4203131046)
Nurul Amaliah Nasution (4203332025)

Course: Hydrocarbon and Its Derivatives
Supporting Lecturer : Dr. Marham Sitorus, M.Si. and Drs. Eddiyato, M.Sc., Ph.D.

STUDY PROGRAM BILINGUAL CHEMISTRY EDUCATION
FACULTY OF MATHEMATICS AND NATURAL SCIENCES

STATE UNIVERSITY OF MEDAN
MAY 2021

CIS-TRANS AND E-Z GEOMETRY
ISOMERS FOR ALKENA

MATERIAL Chemical test Cis-trans and e-z geometry
PRACTICUM isomers for alkena

Do you know? Curiosity

In geometric isomer nomenclature, the prefixes cis- and
trans- are used to identify which side of the double bond similar
atoms are found. The prefix cis- comes from Latin meaning "on
this side". The prefix trans comes from Latin meaning "to cross".

There are two forms of cis-trans isomers, namely cis and
trans. When the substituent groups are oriented in the same
direction, this diastereomer is referred to as cis, whereas when
the substituent is oriented in the opposite direction, the
diastereomer is referred to as trans. An example of a
hydrocarbon molecule showing cis-trans isomerism is 2-butene.

PRACTICUM ADVISORS

CHEMICAL TEST CIS-TRANS AND E-Z
GEOMETRY ISOMERS FOR ALKENA

A. PRACTICUM OBJECTIVES

CHEMISTRY

1. Students are able to know about geometric isomers
2. Students are able to understand the basic principles of space
isomers, especially geometric isomers and understand the
differences in physical properties between cis and trans isomeric
compounds.

B. BASIC THEORY

Curiosity

Stereoisomers can be Geometric isomers are isomers that occur in two
described using other molecules that have the same molecular formula, but
notations besides cis- and differ in the arrangement of the atoms in space. Always
trans-. For example, the remember that the molecules actually exist in three-
dimensional space where the atoms are bonded in such an
E / Z isomer is a arrangement. Geometric isomers occur due to rigidity in
configuration isomer with molecules and are only found in two groups of compounds,
any rotational limitation. namely alkenes and cyclic compounds.
The EZ system is used as
a cis-trans substitute for If a group or atom is bonded by only sigma bonds
(sp3, generally in single-bonded compounds), then the
compounds that have group or atom that is bound can rotate in such a way
more than two that the shape of the molecule will always be the same.

substituents. When used
in a name, E and Z are
italicized.

PRACTICUM ADVISORS

Example :

Unlike the case with groups or atoms that are bound by double
bonds where there are sigma and pi bonds in the molecule (sp2). This
group or atom cannot rotate without first breaking the pi bond. So that
there is a nature of the kinkness of a molecule which causes if the
location of the atom or group is different, then the properties of the
compound are different. This means that the two compounds are
different.
Example :

The two compounds above are different where in the first
compound the location of the Cl atom is side-by-side, while in the
second compound the location of the Cl atom is different. The first
compound is not easily converted into a second compound, and vice
versa because the double bond between the carbon atoms is rigid.

If in a compound, two of the same groups or atoms are located on one
side of the pi bond, it is called cis, and if they are opposite, it is called
trans.

The difference between the two compounds can be proven from
differences in their physical properties such as the boiling points of
the two different compounds. The cis-1,2-dichloroethene compound has

a boiling point of 60 degrees Celsius while the trans-1,2-
dichloroethene compound has a boiling point of 48 degrees Celsius.

PRACTICUM ADVISORS

The requirement for a compound to have a geometric isomer is that

each of the accrbon atoms with a pi (double) bond must bind a

different group.

geometric isomers are common in compounds with c = c bonds where

each c atom binds 2 different atoms

Example: 2 – pentene Note Cooperation
C. PRACTICUM TOOLS AND MATERIAL Responsible
Communicative

Direct your group to

 Tools and Material divide the task of
preparing tools and

 Toothpick materials!
 Plasticine is red → atom c Finish each other's
 Plasticine is green → atom h work well and on time!

D. PRACTICUM PROCEDURES Discuss Group
ion
 TEST
Cooperation
1. first of all make a double bond from c here I
use the example of cis-2 butene and trans-2- Communicati
butene then add 2 more c above it because for
butene it must have 4 c after that add 3 h Discuss the
atoms in the c section above then next to it too results of the
like that and add 1 atom h for each of the 2- observations
bonded parts of c
Okay this is the result of cis -2 butene instructed!

2. for the 2 butene trance we just move the ch3 How were the
and h atoms to match the material that when 2 results of the
atoms are the same on opposite sides it is called observations
trans that occurred?
Okay this is the result of trans-2 butene
Is it in
accordance with

the expected
results?

Respect group
members'
opinions!

PRACTICUM ADVISORS

Quiz Critical thinking

Compare your observations with other
groups? Why does it happen?

Please complete the data below based on the observations obtained!

E. PRACTICUM RESULTS DATA

Num. The Treatment Observation Picture
1 Being Observed
manufacture of cis 2
CIS-2-BUTENA butene done by
making a double bond
of the c atom, and
the next 2 c atoms,
and making 3 H atoms
on the right and on
the left as well as
below

2 TRANS-2- manufacture of a

BUTENA butene trance 2 is

done by moving the

CH3 atom downward

PRACTICUM ADVISORS

Note Responsible

F. EVALUATION Answer the following questions!

1. Draw all the isomers of the compound with the
molecular formula C5H120
………………………………………………………………………………………………
………………………………………………………………………………………………

2. Determine whether the following compounds have cis-
trans geometric isomerism.

a) 1,2-dikloroetena
b) 2-butuna

……………………………………………………………………………………………………………
……………………………………………………………………………………………………………

3. Determine whether the following compounds have optical
isomers or not

a. asam 2-hidroksipropanoat (asam laktat)
b. 2-bromopropana

…………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………….

PRACTICUM ADVISORS

G. PRACTICUM CONCLUSION

Write conclusions based on
practicum goals and observations that
have been made!

Communicative

Isomers are the relationship between two or more compounds that

have the same chemical formula but have different structures or

configurations are called isomerism (isomerism).

Geometric isomers are isomers that occur in two molecules that

have the same molecular formula, but differ in the arrangement of the

atoms in space. Always remember that the molecules actually exist in

three-dimensional space where the atoms are bonded in such an

arrangemen.
…………………………………… .... …………… … .... ………….
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………………………………… … .... ……………… ...

H. REFE…R…E…N……C…E…S………………………………………………………..….. …………………………………...…. …………………. .
…………………………………………………………………….
………………………………… … .... ……………… ...

https://www.studiobelajar.com/isomer/

https://drive.google.com/drive/folders/1C8_iWo2jlEL9SwpSQ_Jja1
K1e8J8YOks?usp=sharing

Responsible

PRACTICUM ADVISORS

NEWMAN PROJECTION MOLECULAR MODEL
FROM ECLIPSED, STAGGERED AND ANTI FOR

THE n-butane MOLECULE

MATERIAL Chemical test for newman projection
PRACTICUM molecular model from eclipsed, staggered

and anti for the n-butane molecule

Do you know? Curiosity

The Newman projection, useful in stereochemistry of alkanes,
visualizes the front-to-back conformation of a chemical bond, with the
front atom represented by a dot and the back carbon as a circle. The front
carbon atom is called proximal, while the back atom is called distal

The Newman projection is a stereoisomerism of molecules with the
same structural formula but different conformations due to the rotation of
atoms in chemical bonds. Different conformers can change each other by
rotating the single bond without breaking the chemical bond. The existence
of more than one conformation, usually with different energies, is due to
the hindered rotation of the sp3 hybridization orbital of the carbon atom.
Conformational isomerism only occurs in single bonds because double bonds
and triple bonds have pi bonds that prevent bond rotation.

PRACTICUM ADVISORS

CHEMICAL TEST NEWMAN PROJECTION
MOLECULAR MODEL FROM ECLIPSED,

STAGGERED AND ANTI FOR THE n-butane
MOLECULE

A. PRACTICUM OBJECTIVES

CHEMISTRY

1. Students are able to know about newman projection molecular
model from eclipsed, staggered and anti for the n-butane molecule.

2. Students are able to understand newman projection molecular
model from eclipsed, staggered and anti for the n-butane molecule.

B. BASIC THEORY

Curiosity Conformation is a momentary (temporary) molecular
shape as a result of the rotation of a single bond. The
The Newman projection is form of this conformation itself is divided into 3, namely
used primarily to determine Fischer, Ball Pegs, and also Newman. Each of these
forms of conformation itself can conform to the types
conformational of isomeric conformations that are present. In this case
relationships. Keep in mind there are three types of isomeric conformations, namely
Eclips, Staggered Gausch and Staggered Anti.
that conformers are
molecules that can be The Newman projection is a form of molecular
converted into one another stereoisomerism with the same structural formula but
by rotation around a single different conformations due to rotating atoms in
chemical bonds. The different conformers can change
bond. The Newman from each other by twisting single bonds without
projection is also useful breaking the chemical bond. The Newman projection,
when studying reactions useful in alkane stereochemistry, visualizes the

involving prochiral
molecules having a double
bond, in which the addition
of a new group creates a

new stereo center.

PRACTICUM ADVISORS

conformation of a chemical bond from front to back,
with the front atom represented by a dot and the back
carbon as a circle.

Conformational isomerism (Newman projection) is a
form of stereoisomerism of molecules with the same
structural formula but different conformations due to
the rotation of atoms in chemical bonds. The different
conformers can change with each other by rotating the
single bond without breaking the chemical bond. The
existence of more than one conformation, usually of
different energies, is due to the hindered rotation of
the sp3-orbital hybridization of the carbon atom.
Conformational isomerism only occurs in single bonds
because double and triple bonds have pi bonds which
prevent bond rotation.
1. Eclipsed conformation.
It is a molecular conformation in which atoms and groups are
located side by side, resulting in electron repulsion which results in this
conformation being the most unstable conformation.

2. Gausch's Staggered Conformation.
It is a molecular conformation in which the atoms and groups

undergo rotation so that they are located far apart from each other.

3. Anti Staggered Conformation.
It is a molecular conformation where the atoms and groups are

located opposite, resulting in a small repulsion which results in this
conformation being the most stable conformation.

PRACTICUM ADVISORS

C. PRACTICUM TOOLS AND MATERIALS

Note Cooperation
Responsible
Communicative

 Tools

 Google Jamboard Direct your group to
 images from google include eclipsed, divide the task of
preparing tools and
staggered gauche, and anti staggered materials!
Finish each other's
images. work well and on time!

D. PRACTICUM PROCEDURES Discussi Group
on
 TEST
Cooperation
 Here we use Google Jamboard as a virtual whiteboard Communicative
then we insert images including: n-butane, eclipse,
staggered gauche, and anti staggered images. Then Discuss the results
we make sense of each conformation by typing it of the observations
directly into the Google Jamboard.
instructed!

How were the
results of the
observations that

occurred?

Is it in accordance
with the expected

results?

Respect group
members' opinions!

PRACTICUM ADVISORS

Quiz Critical thinking

Compare your observations with other
groups? Why does it happen?

Please complete the data below based on the observations obtained!
E. PRACTICUM RESULTS DATA

Num. The Treatment Observation Picture
1 Being Observed
Eclipsed is the most
2 Eclipsed unstable conformation
and the methyl groups
3 Staggered are parallel and the
Gauche methyl groups cannot
form an angle or have an
Staggered angle of 0°.
Anti Staggered gauche is the
shape after the rotation
that occurs in the
eclipsed conformation of
the methyl group in this
conformation forming an
angle of 60°.
Staggered anti is the
most stable conformation
and the methyl group can
form an angle of 180°.

PRACTICUM ADVISORS

Note Responsible

F. EVALUATION

Answer the following questions!

1. Why is the eclipsed conformation said to be the least

stable conformation?
…………………………………………………………………
…………………………………………………………………

2. Why is the Staggered Anti conformation said to be
the most stable conformation ?
……………………………………………………………………………………………………
…………………………………………………………………………………………………….

G. PRACTICUM CONCLUSION

Write conclusions based on
practicum goals and observations
that have been made!

Communicative

Conformation is a momentary (temporary) molecular shape as a result of

the rotation of a single bond. The form of this conformation itself is divided

into 3, namely Fischer, Ball Pegs, and also Newman.

The Newman projection is a form of molecular stereoisomerism with the

same structural formula but different conformations due to rotating atoms in

chemical bonds. The different conformers can change from each other by

twisting single bonds without breaking the chemical bond.
……………………………………………………………………. …………………………………… ....

…………… … .... ………….
…………………………………………………………………….
………………………………… … .... ……………… ...

……………………P…RA…C…TI…CU…M…A…D…V…IS…OR…S………………….

…………………………………… .... …………… … .... ………….
…………………………………………………………………….

H. REFERENCES

https://maknaorganik.blogspot.com/2019/08/konformasi-struktur.html
https://www.slideshare.net/ReskianiEmbatau/konformasi-isomer
https://alfulailaariyanti.blogspot.com/2019/08/kimia-organik-3-konformasi-
struktur-dan.html
https://maknaorganik.blogspot.com/2019/08/konformasi-struktur.html

Responsible

PRACTICUM ADVISORS