Chemistry Question

Using robust details and ample evidence, create a reflective essay that describes the learning objectives you met while performing this experiment.  View the learning objectives from the lab manual provided and select four to focus your writing on.

Please refer to the scoring rubric for grading details.

there are 2 lab manuals so it will be 2 reflection essays, each one should be 250 words minimum. one of the manuals is 2 (Ceric Ammonium Nitrate) learning objectives and the other one is 3 (Hydrocarbon Nomenclature and Representations). use only these objectives to write the reflection essay.

Virtual Lab Manual
Hydrocarbon Nomenclature and
Representations
Synopsis
What’s in a name? In this simulation, you will learn how to name the hydrocarbons – the core
part of organic compounds. You will also be challenged with various ways of representing
chemical structures in 2D, and learn to decide when to use which one.
Organic chemical compounds
You will start off by meeting with Simon, who’s having trouble figuring out the ins and outs of
the fundamentals within organic chemistry. He’s especially lost on how the naming works –
which is known as the nomenclature. Perhaps you will be able to sort him out?
Match 2D structure with name and 3D visualization
In the lab, you join forces with Dr. One, who will support and test you on your mission. Begin
by suiting up for the lab and getting a quick briefing on how the nomenclature works for
hydrocarbons. Then dive straight in to the challenge of figuring out the appropriate name for
a given 2D structure, helped by 3D molecular visualization on your holotable.
A chemical formula type for every need
In the challenge above, you’ll be exposed to a specific type of 2D representation of
molecules. There are several other types of these representations, though; also called
formula. Which one is appropriate to use when? You will explore this on the lab’s interactive
wall screen, where you need to assess the strengths and weaknesses of the common types
of formula.
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Returning to Simon
Armed with all your new knowledge, you will return to Simon to share all you’ve learnt. It’s a
tricky topic though, but luckily you can repeat the experience if you want to drive the points
in even further. Will you be able to solve the hydrocarbon nomenclature challenge?
Learning Objectives
At the end of this simulation, you will be able to…
● Apply the nomenclature of simple hydrocarbons to given 2D and 3D structures
● Interpret the core formula types for organic compounds
● Decide the appropriate chemical formula type to use for a given hydrocarbon
Techniques in Lab
None
Theory
Aromatic rings
Aromatic rings are a common group in organic chemistry. They are planar ring systems, where
a series of double bonds make the molecule conjugated, which means that the p orbitals
used for the π bonds overlap with p orbitals on both sides of each carbon atom. Figure 16
shows benzene, one of the simplest aromatic compounds. Though commonly drawn like this,
each carbon in the compound is actually bonded in the exact same way to both of its
neighbors.
Figure 1: She structure of benzene, one of the simplest aromatic compounds.
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Functional groups
Functional groups are the parts of a molecule responsible for its reactivity. Different
functional groups give rise to different reaction types in organic chemistry.
Functional groups can be a specific arrangement of carbon and hydrogen, e.g. a double bond,
or can also include other elements. The most common elements in organic compounds
besides carbon and hydrogen are oxygen and nitrogen. Other examples of elements are
phosphorus and halogens. You can see the functional groups of salicylic acid in Figure 2.
Figure 2: The functional groups of salicylic acid. Purple = phenol; green = carboxylic acid; blue
= phenyl.
Hydrocarbons
Hydrocarbons are a subgroup of organic compounds, which contain only carbon and
hydrogen. Examples of hydrocarbons can be seen in Figure 3.1. Salicylic acid, shown in Figure
3.2, is an organic compound, but it’s not a hydrocarbon as it contains oxygen groups.
Figure 3.1: Structure of the hydrocarbons methane, propane, and 1-butene.
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Figure 3.2: Structure of the hydrocarbons methane, propane, and 1-butene.
Hydrocarbon prefixes
Prefixes for simple hydrocarbons are determined by the number of carbon atoms in the
longest carbon chain. Figure 4 shows the general principle of assigning prefixes regardless of
the type of bonds involved in the compound.
Figure 4: Role of the prefixes in names of hydrocarbons.
Hydrocarbon side groups
Side groups of only carbon and hydrogen in organic compounds have the same prefixes as
the hydrocarbons. The suffix used is -yl.
If there are side groups on the longest chain of carbon atoms, these are numbered by the
carbon they are attached to. The carbon number for this group of organic compounds is
assigned so:
1) You always count from one end of the longest carbon chain with the most
important functional group
2) If a double or triple bond is present, this should get the lowest number possible
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3) If only single bonds are present, the side groups should get the lowest number
possible
If a side group can only be positioned in one place in the compound, the number can be
omitted.
Check out the examples from the simulation in Figure 5.1 and 5.2 to see how the numbers are
assigned:
Figure 5: More examples of hydrocarbons with side groups.
Hydrocarbon suffixes
Suffixes for simple hydrocarbons are determined by the type of bonds present. See figure
below which suffixes apply.
Figure 6: Overview of hydrocarbon suffixes.
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List of hydrocarbon prefixes
The following table shows the prefixes for hydrocarbons with 1-10 carbon atoms present in
the longest carbon chain. Note that only the prefix is shown in the second column and that
the whole name includes the suffix, which for hydrocarbons depend on whether double or
triple bonds are present in the compound.
Table 1. List of prefixes in names of hydrocarbons and examples of complete names.
NUMBER OF CARBON ATOMS
1
2
3
4
5
6
7
8
9
10
PREFIX
MethEthPropButPentHexHeptOctNonDec-
COMPOUND EXAMPLE
Methane
Ethene
Propyne
1-Butene
Pentane
3-Hexyne
2-Heptene
Octane
1-Nonyne
4-Decene
Nomenclature of simple hydrocarbons
Simple hydrocarbons are named based on a few straightforward rules. The first part of the
name – the prefix – is determined by the number of carbon atoms in the longest carbon
chain. The second part of the name – the suffix – is determined by whether double or triple
bonds are present. A visual representation of these principles can be seen in Figure 7.
Figure 7: Overview of the nomenclature principles of simple hydrocarbons.
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If more than one location is possible for a double or triple bond, a number is added to
indicate its placement on the carbon chain, always counting from one end of the chain and
giving the carbon the lowest number possible.
Representations in 2D of hydrocarbons
There are numerous ways to represent the elements and structure of a chemical compound.
Below you will find some of the most common types used for organic compounds, each with
different strengths and weaknesses. Be aware that variations of each type are not
uncommon, usually when certain molecule groups or bonds are to be emphasized.
●
Molecular formula – The molecular formula gives the total number of each element
present in the compound. It does not reveal any information about the structural
arrangement of the elements though.
●
Displayed formula – The displayed formula writes out the entire structure of the
compound in detail, showing all elements and bonds. It can quickly become hard to
read though for larger and more branched compounds.
●
Partially condensed formula – A representation similar to the displayed formula, but
where all bonds to hydrogen are hidden, or “condensed”.
●
Condensed formula – In the condensed formula, the structure is written as an
equation based on the carbon backbone, with all bonds hidden and side groups
grouped together. Sometimes, double/triple bonds are explicitly shown for clarity.
●
Skeletal formula – In the skeletal formula, all carbons and hydrogens are hidden.
Carbons are implied at the vertices (corners and end points) of the drawn structure,
and the number of hydrogens is inferred by always assuming four bonds for each
carbon. When going beyond hydrocarbons and including functional groups, hydrogens
will usually be explicitly drawn when they are part of a functional group.
Figure 8: The hydrocarbon 2-methyl-but-2-ene shown in various types of formula and 2D
representations.
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Saturated vs. unsaturated hydrocarbons
A hydrocarbon is saturated if it contains no double or triple bonds. If either of these is
present in a compound, this will make it unsaturated. Figure 8 shows a visual representation
of this principle.
Figure 9: Overview of saturated vs. unsaturated compounds.
The molecular formula of a non-cyclic alkane will follow this rule for the number of carbons
and hydrogens: CnH ₂n+₂.
Non-cyclic alkenes follow this rule: CnH₂n.
Non-cyclic alkynes follow this rule: CnH₂n-₂.
Skeletal formulas
Skeletal formulas are a simplified way of representing organic compounds. Instead of writing
out all the carbon and hydrogen atoms, they are implied by corners, also called ‘vertices’, in
the structure. See for example Figure 1. Only carbon and hydrogen can be omitted this way.
Figure 9. The organic molecule benzene with all atoms drawn out (Structure A), and the
simplified skeletal structure (Structure B), which is commonly used. The skeletal structure of
salicylic acid with molecular formula C 7H6O3(Structure C)
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Skeletal structures are a great way to more clearly show important aspects like functional
groups of an organic compound, see Figure 2 for the skeletal structure of salicylic acid. A
combination of the two ways of drawing the structure can be used as well.
The nature of organic compounds
Organic chemistry is the study of organic compounds and their structure, properties, and
reactions. Organic compounds are chemicals that are based on the element carbon, and
most often they would also contain bonds between carbon and hydrogen. Methane, a
hydrocarbon, shown in Figure 10, is one of the simplest organic compounds.
Figure 10: Structure of methane, a simple organic compound.
Many organic compounds contain elements other than carbon and hydrogen, typically oxygen
and nitrogen, but it can also be other groups such as phosphorus or halogens.
Some carbon compounds are not considered to be organic, e.g. carbonates and carbon oxides
like carbon monoxide and carbon dioxide. These types of compounds are regarded as
inorganic.
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