Download Molecules 1 and Molecules 2

Experiment Description/Manual for the Science Kit
Molecules 1
and
Molecules 2
Molecules 1 and Molecules 2
Science box Molecules 1 Order no. 18474
contains the basic elements for the assembly of atomic
models of alphatic compounds.
Science box Molecules 2 Order no. 31810
only to be used together with the box Molecules 1, to
build up organic compounds.
Science kit Molecules 1
31764
Science kit Molecules 2
42880
Order no. 31764
contains 10 boxes Molecules 1
Teacher´s manual Molecules
Science kit Molecules 2 Order no. 42880
contains 10 boxes Molecules 2
Teacher´s manual Molecules
Science kit Molecules 3
36685
2
Science kit Molecules 1 Science kit Molecules 3 Order no. 36685
contains each 5 boxes Molecules 1 and Molecules 2
Teacher´s manual Molecules
Molecules 1 and Molecules 2
Science Boxes
Molecules 1 and Molecules 2
Contents
List of components............................................................................................... 4
Table of components............................................................................................ 5
General Instructions ............................................................................................. 6
1.
Notes on ball-and-rod models ................................................................... 6
2.
Applications of the Molecules 1 and Molecules 2 science boxes............... 6
3.
Representing compounds with the
Molecules 1 and Molecules 2 science boxes .............................................. 6
4.
Teaching Notes........................................................................................... 8
5.
A selection of important compounds......................................................... 8
5.1Alkanes ........................................................................................................ 8
5.2
Alkenes (olefins)........................................................................................... 8
5.3Alkines ......................................................................................................... 8
5.4
Halogen derivatives of the alkanes................................................................ 8
5.5
Alkanoles (alcohols) ..................................................................................... 8
5.6
Alkanales (aldehydes)................................................................................... 9
5.7
Formation of high-molecular weight plastic
Conversion of ethylene into polyethylene..................................................... 9
5.8
Amino acids, proteins................................................................................... 9
5.9
Molecules of some elements ...................................................................... 10
5.10Carbohydrates ........................................................................................... 10
5.11 Carboxylic acids......................................................................................... 12
5.12 Fat synthesis from oleic acid, butyric acid, stearic acid and glycerol............. 12
5.13 Fat saponification....................................................................................... 13
5.14 Synthetic detergents.................................................................................. 13
5.15 Aromatic hydrocarbons.............................................................................. 14
5.16 Condensed aromatic rings ......................................................................... 14
5.17 Benzene ring substitution........................................................................... 14
5.18Dyes .......................................................................................................... 15
5.19Drugs ........................................................................................................ 15
© 2008 Cornelsen Experimenta, Berlin
All rights reserved.
The work and parts of it are protected by copyright.
Every use for other than the legal cases requires the previous written agreement by Cornelsen Experimenta.
Hint to §§ 46, 52a UrhG: Neither the work or parts of it are allowed to be scanned, put into a network or otherwise
to be made publicly available without such an agreement.
This includes intranets of schools or other educational institutions.
We assume no liability for damages which are caused by inappropriate usage of the equipment.
3
Molecules 1 and Molecules 2
List of components
Illustr. no. Qty. Description
Order no.
Science Box Molecules 1, containing............................................ 18474
1
2
3
4
5
6
60 25 15 5
5
14 Connecting rods, grey................................................................... 18547
Hydrogen (H), monovalent, white.................................................. 18490
Oxygen (O), bivalent, red.............................................................. 18512
Chlorine (Cl), monovalent, green................................................... 18504
Nitrogen (N), trivalent, blue........................................................... 18520
Carbon (C), quadrivalent, black..................................................... 18539
Science Box Molecules 2, containing............................................ 31810
7
8
9
10
11
12
13
14
15
1
80 4
3
8
4
4
8
4
4
4
Connecting rods, grey................................................................... 18547
Universal building blocks, grey....................................................... 39358
Benzene rings, black...................................................................... 39340
Sulphur (S), bivalent, yellow........................................................... 39315
Oxygen (O), bivalent, red.............................................................. 18512
Nitrogen (N), trivalent, blue........................................................... 18520
Carbon (C), quadrivalent, black..................................................... 18539
Phosphorus (P), pentavalent, violet................................................ 39323
Nitrogen (N), pentavalent, blue..................................................... 39331
Sulphur (S), hexavalent, yellow...................................................... 39307
Enclosed printed material per Box:
–1
Student’s manual
“Molecules 1 and Molecules 2”................................................. 184746
Also available:
Science Kit Molecules 1 (description on page 2)........................... 31764
Science Kit Molecules 2 (description on page 2)........................... 42880
Science Kit Molecules 3 (description on page 2)........................... 36685
Enclosed printed material per Kit:
–1
Teacher’s manual
“Molecules 1 and Molecules 2”................................................. 366856
–10
Student’s manuals
“Molecules 1 and Molecules 2”................................................. 184746
–1
Storage plan Molecules 1, DIN A3..............................................3176436
or
–1
Storage plan Molecules 2, DIN A3............................................ 4288036
or
–1
Storage plan Molecules 3, DIN A3............................................ 3668536
4
Molecules 1 and Molecules 2
Table of components
Science Box Molecules 1:
1
2
3
4
5
6
Science Box Molecules 2:
7
8
9
10
11
12
13
14
15
16
5
Molecules 1 and Molecules 2
General Instructions
The molecule models are assembled simply by linking
up the models of the atoms using the connecting
rods. The rods are flexible, so that they can also be
used to show multiple bonds (double, triple).
Models requiring a very large number of atoms can
be assembled using components from more than one
Molecule box. The models of the atoms have been
designed to join up at the spatially correct angles.
The colour coding of the different atoms follows international conventions. In addition, each atomic model
bears the appropriate chemical symbol.
After use, the individual components should be placed
in the box as shown in the illustration on page 5 to
facilitate checking whether all components are
present.
1. Notes on ball-and-rod models
Ball-and-rod models of molecules can be built with
the science boxes Molecules 1 and Molecules 2.
These models are particularly suitable for depicting
the stoichiometric valency and the spatial arrangement of atom centres within a molecule, but do not
accurately demonstrate the proportions of atomic
shells or the differences between σ and π-bonds.
Generally speaking, models only represent a few
aspects of reality and therefore when using a model,
the significance of all building blocks must be clear.
The balls represent individual atom centres
(the different dimensions of the atomic shells
are not taken into account). Each vacant plug
on a ball stands for a missing electron, and each
connecting rod for a binding electron pair.
With ball-and-rod models it is only possible to build
molecules with covalent bonds (also molecules of
elements) or ions, provided they are made up of
molecules. Cations are represented by vacant plugs,
and anions by connecting rods on plugs.
The following cannot be represented by ball-and-rod
models:
•
6
ionic compounds which form ionic (polar)
crystals, e.g. NaCl;
•
compounds with hydrogen bridges, etc., e.g.
polypeptide chains;
•
mesomeric states of systems (though their
resonating structure can be demonstrated)
The example of the diamond lattice on page 8 shows a
crystalline structure, though this is not a contradiction
of the above. The bonds between the individual carbon
atoms in diamond are covalent.
Benzene plays a special role in chemistry lessons.
Hence, it was deemed appropriate to deviate from
the ball-and-rod model for this single substance.
For building aromatic hydrocarbons, the science
box contains three special benzene building blocks
to provide a more detailed insight into the spatial
arrangement within the molecule.
2. Applications of the Molecules 1 and Molecules 2 science boxes
The science box Molecules 1 generally suffices for
O-Level chemistry lessons. However, in order to represent important organic compounds in schools
offering advanced chemistry, science box Molecules
2 is generally also necessary (science box Molecules
2 can only be used in conjunction with science box
Molecules 1). In this manual, those molecule models
which go beyond the scope of the Molecules 1 kit are
labelled accordingly.
3. Representing compounds with the Molecules 1 and Molecules 2
science boxes
To keep the number of different building blocks to
a minimum, the science boxes do not accurately
portray the various bond angles. The atom models
are designed such that students can dispense with
instructions as to how the molecules are assembled.
Nonetheless, the bond angles between the atom
centres are portrayed as useful spatial approximations.
Molecular structures can therefore be demonstrated
clearly.
Should assistance prove necessary during assembly, the
models are illustrated in the teacher’s manual in such a
manner that they can be easily put together.
The realistic model representation of the sulphone
group, nitro group and phosphorus-oxygen group
Molecules 1 and Molecules 2
places high demands on students’ 3-dimensional
visualisation skills. The following illustrations serve as
information for teachers and show the correct configurations as well as one possible incorrect structure
for the individual groups.
O
Sulphone group
SO2¯¯
S
O
mechanisms, e.g. cracking process, breakdown of
disaccharides and polysaccharides into monosaccharides, isomerism, substitution, addition, polymerisation, polyaddition, polycondensation etc.
Models are particularly indispensable when it comes
to understanding isomerism, and in the hands of
students, they enhance the results of the learning
process.
The models also show the differences with respect
to the size and geometry of molecules, on which the
properties of various substances depend (melting
point, boiling point, stability etc.). The geometry of
molecules can also be elucidated using the Gillespie
and Nyholm theory (electron-pair repulsion model).
(Tetrahedral bond orientation)
(incorrect)
O
NO2¯
Nitro group
N
O
The mean distance between the centres of adjacent
atoms in a compound is approximately 0.15
nanometres (nm). (1 nm = 10-6 mm = 0.000001 mm)
In the model, this distance is about 5.6 cm. From the
length of a molecule model, the actual length of the
molecule can be approximated.
Example (n-butane, C4H10):
(Planar bond orientation, α = β)
Phosphorus-oxygen group
(incorrect; α ≠ β)
Length of the n-butane molecule model: 24 cm
Length of the n-butane molecule: X
O
OP O
PO4¯¯¯
O
5.6 cm : 0.15 nm = 24 cm : X
or
X : 24 cm = 0.15 nm : 5.6 cm
X=
(Tetrahedral bond orientation)
(incorrect)
The colours used for the various atom types comply
with international conventions. Furthermore, each
atom model is embossed with the respective chemical
symbol.
In addition to greatly facilitating the derivation of
empirical and structural formulas, the molecule
models also make it possible to demonstrate and
interpret numerous phenomena and reaction
or, solving for X:
24 cm
5.6 cm
. 0.15 nm ≈ 0.65 nm
Therefore, the length of the n-butane molecule is
approximately 0.00000065 mm.
The molecule models are built by simply linking the
atom models with the connecting rods. Multiple
bonds (double and triple bonds) can also be represented by means of the flexible connecting rods.
Where appropriate, models consisting of a greater
number of atoms can be assembled using the
components from several boxes.
7
Molecules 1 and Molecules 2
4. Teaching Notes
Given below are examples of compounds for which
science box molecular models can be assembled.
In each case both the empirical and structural
formulae are given, in many cases the model is also
shown.
If the aim of the lesson is to work with the models
then determine the structural formulae and work out
empirical or group formulae, it is advisable not to
use the examples of the manual at first. However, the
manual provides a good basis to work from whenever
rapid assembly of the models is important, for
instance with more extensive models.
5. A selection of important compounds
5.1 Alkanes: empirical formula CnH2n+2
e.g. 1 Methane CH4
3 Propane C3H8
2 Ethane C2H6
i-Butane C4H10
4 n-Butane C4H10
5.2 Alkenes (olefins): empirical formula CnH2n
5.3 Alkines: empirical formula CnH2n-2
e.g. 5 Ethene (ethylene) C2H4
e.g. 6 Ethine (acetylene) C2H2
5.4 Halogen derivatives of the alkanes:
e.g. 7 Monochlormethane (methylchloride) CH3Cl
5.5 Alkanoles (alcohols): empirical formula for a primary alcohol CnH2n+1OH
e.g. 8 Methanol (methyl alcohol) CH3OH
9 Ethanol (ethyl alcohol) 10 Propanetriol (glycerol) CH2OH-CHOH-CH2OH
C2H5OH
8
Please also see 5.12
Fat synthesis.
Molecules 1 and Molecules 2
5.6 Alkanales (aldehydes): empirical formula: R-CHO
11 Methanal (formaldehyde) 12 Ethanal (acetaldehyde) HCHO
CH3CHO
5.7 Formation of high-molecular weight plastic
13 Conversion of ethylene into polyethylene:
+
+
...
Ethylene
...
..
Polyethylene
5.8 Amino acids, proteins
e.g. Formation of a dipeptide 16
from two amino acids
Formation of a polypeptide from several
simple amino acids
14 Aminoacetic acid (glycine)
Glycine
Adenosine triphosphate (ATP)
15 Alanine
Glycine
Material taken from each one box Molecules 1 and 2.
9
Molecules 1 and Molecules 2
5.9 Molecules of some elements
S8
H2
Material taken from each one box Molecules 1 and 2.
Carbon lattice in
diamond
N2
5.10 Carbohydrates
Breakdown of cane sugar 19 to grape sugar 17 and fruit sugar 18 (hydrolysis)
C12H22O11 + H2O
C6H12O6 + C6H12O6
CH2OH
H
H
OH
O
H
HO
H
H
OH
O
CH2OH
OH
H
H HO
HOCH2
O
H
CH2OH + H2O
HO
H
17 Glucose
10
H
OH
H
O
H
OH
H
OH
OH
18 Fructose
HO
+
HOCH2
H
H HO
O
CH2OH
H
Molecules 1 and Molecules 2
5.10 Carbohydrates
Material taken from two Molecules 1 boxes.
Polysaccharides
e.g. 20 Starch (C6H10O5)n
n = 50 . . . 5000
One starch molecule is formed by many grape sugar units on losing water (polycondensation):
The cellulose molecule 21 , like the starch molecule, is made up of numerous grape sugar groups.
The number of C6H10O5-groups in a cellulose molecule is estimated to be about 10,000.
11
Molecules 1 and Molecules 2
5.11 Carboxylic acids Examples:
26 Empirical formula of
22 Methanoic acid (formic acid)
23 Ethanoic acid (acetic acid)
HCOOH
CH3COOH
24 Propanoic acid (propionic
25 Butanoic acid (butyric acid)
CH3-(CH2)2-COOH
monocarboxylic acids: R-COOH
acid) CH3-CH2-COOH
Fragment R can be represented using
a universal building block from the
Molecules 2 box.
5.12 Fat synthesis from oleic acid, butyric acid, stearic acid and 10 glycerol
Material taken from four Molecules 1 boxes.
Other spatial arrangements within the fat molecule are also possible.
12
Molecules 1 and Molecules 2
5.13 Fat saponification
Material taken from one Molecules 1 box and two Molecules 2 boxes.
The fragment (labelled universal building block) has the formula –C17H35
CH2OOCC17H35 CH2OH
+CHOOCC17H35 3 NaOH +
3 C17H35COO Na + CHOH
CH2OOCC17H35 CH2OH
For all the following connections each one box Molecules 1 and 2 is required.
5.14 Synthetic detergents
Fatty alcohol sulphates
Alkylaryl sulphonates
- +
R-O-SO3 Na
Alkyl sulphonates
R–
+
R-SO3-Na
+
-SO3- Na
The group has the empirical formula CH3-(CH2)n13
Molecules 1 and Molecules 2
5.15 Aromatic hydrocarbons
Example of a cyclic, non-aromatic compound:
27 Cyclohexane C6H12
28 Benzene
Representation of benzene
molecule with the components
from the Molecules 1 box
Unlike the benzene molecule, the cyclohexane
molecule is not planar.
Only Molecules 1 box required.
5.16 Condensed aromatic rings
29 Naphthalene
Anthracene
5.17 Benzene ring substitution
28 Benzene
14
30 Nitric acid
31 Nitrobenzene
Water
Molecules 1 and Molecules 2
5.17 Benzene ring substitution
28 Benzene
Sulphuric acid
Benzene monosulfonic acid
Water
5.18 Dyes
In the given examples, the colouring is caused by delocalised electron systems within the molecules
(mesomeric systems). However, mesomeric systems are not distinguished as such in models
constructed using the Molecules boxes, but are shown as groups of electron-pair bonds
(see Chapter 1 of this manual).
p-Nitraniline
32 Methyl orange (the Na+ ion is represented
by a universal building block)
5.19 Drugs
Sulphathiazole
33 Penicillanic acid
15
Experiment Description/Manual Science Kit „Molecules 1 and Molecules 2“
Order no. 36685 6
Holzhauser Straße 76
13509 Berlin – Germany
© 2008 Cornelsen Experimenta, Berlin Tel.: +49 30 435 902-0
Fax: +49 30 435 902-22
eMail: [email protected]
Internet: www.corex.de
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