Cyclohexane

In: Science

Submitted By muftiya10
Words 1335
Pages 6
Identification of Unknown Organic Compounds

Introduction

The identification and characterization of the structures of unknown substances are an important part of organic chemistry. Although it is often possible to establish the structure of a compound on the basis of spectra alone (IR, NMR, etc.), the spectra typically must be supplemented with other information about the compound: physical state and properties (melting point, boiling point, solubility, odor, color, etc.), elemental analysis, and confirmatory tests for functional groups.

In this experiment you will carry out several qualitative tests that will allow you to identify functional groups in organic molecules. You will then apply what you have learned by characterizing unknown organic compounds in terms of their functional group and solubility behavior. The functional groups you will examine include amines, alcohols, carboxylic acids, alkenes, alkanes, and alkyl halides.

Solubility and Functional Group Tests

Each functional group has a particular set of chemical properties that allow it to be identified. Some of these properties can be demonstrated by observing solubility behavior, while others can be seen in chemical reactions that are accompanied by color changes, precipitate formation, or other visible effects.

1. Solubility Tests

The solubility of an organic compound in water, dilute acid, or dilute base can provide useful information about the presence or absence of certain functional groups. A flowchart showing the sequence of solubility tests along with the appropriate conclusions is shown in Figure 1.

Solubility in water: Most organic compounds are not soluble in water, except for low molecular-weight amines and oxygen-containing compounds. Low molecular-weight compounds are generally limited to those with fewer than five carbon atoms.

• Carboxylic…...

Similar Documents

Purification of Organic Compounds

...liquid. Depending on the difference in boiling points of liquids. Types of distillation Simple Distillation Fractional Distillation Distillation Under Reduced Pressure or Vacuum Distillation Steam Distillation 9. SIMPLE DISTILLATION Principle It is used for separating liquids having boiling points differing by 10-20 degrees. The liquid having the lower boiling point distills over first, and the other liquid component is left behind. In this process, vaporization and condensation occur side by side. Process Example Simple distillation of a Cyclohexane- Toluene mixtures 10. Fig : - Simple distillation 11. FRACTIONAL DISTILLATION Principle It is used for separating two liquids in any mixture, which have boiling points within a narrow range of temperatures. In such cases, simple distillation does not give complete separation and a modified version called fractional distillation is employed. Process Example Fractional Distillation of a Cyclohexane- Toluene mixtures 12. Fig : -Fractional distillation 13. DISTILLATION UNDER REDUCED PRESSURE OR VACUUM DISTILLATION Principle The lowering of pressure on the surface of a liquid lowers its boiling point. As a result of this, a liquid can be boiled and distilled, without any decomposition, at temperature much below its normal boiling point. Process 14. STEAM DISTILLATION Principle This technique is used for separating/purifying liquids, which are immiscible with water, volatile in steam, & have high vapor pressure at the boiling......

Words: 853 - Pages: 4

Azeotropic Distillation

...distillation to describe the fact that the entrainer will form an azeotrope with one or more of the components of the initial azeotropic mixture, enabling separation of the remaining constituents by a distillation process. It compares to homogenous distillation whereby the entrainer is completely miscible with the liquid. Depending on whether a single component or all the components of an azeotrope need to be separated, continuous distillation is carried out, until the desired constituent is achieved. For the case of a water/ethanol azeotrope, we use benzene or cyclohexane as an entrainer. The addition of this third party component changes the molecular interactions between water and ethanol and eliminates the binary azeotrope to form a ternary azeotrope. With cyclohexane as an entrainer the ternary azeotrope is 7% water, 17% ethanol, and 76% cyclohexane. It boils at a temperature of 62.1°C. The addition of the cyclohexane engages all of the water in the tertiary azeotrope so that when the mixture is boiled, the azeotrope vaporizes, leaving a residue composed almost entirely of the excess ethanol. The downside of using a third party component such as benzene is that the pure ethanol extract is no longer suitable for consumption, as small amounts of benzene used remain in the solution and the latter is known to be carcinogenic. At this stage it is usually used as a gasoline additive. There are alternatives to azeotropic distillation, such as pressure swing......

Words: 925 - Pages: 4

Hello

...bromochloroiodomethane and 2-hydroxypropanal (see below). 6. How many optical isomers possesses compound with one and more asymmetric carbon atoms? 7. The principle of drawing of the spatial projections of chiral compounds. 8. The principle of drawing compound formulas in Fisher projection. 9. The principle of assigning the absolute configuration of chiral atoms? – Cahn-Ingold-Prelog’s Rule. Please visit Wikipedia website of excellence (medal-awarded): http://pl.wikipedia.org/wiki/Konfiguracja_absolutna Unfortunately, the webpage is in Polish. It might be useful to enhance the English version of the website for the forthcoming ‘Macro’ generations. 10. Stereochemistry of cyclobutane, cyclopentane and cyclohexane rings. Conformers. Inversions of the ring. Mono-, di- and tri-substituted the above carbon-rings. 11. Assign the absolute configuration of: [pic] 12. Draw in the spatial projections the R-enantiomers of: phenylglycine (2-amino-2-phenylacetic acid) 1-chloro-2,3-dibromopropane 2-methylpentane 1,2-dihydroxypropane 3-amino-2-methylpropanol 2-butanol 13. Draw in the spatial projections the S-enantiomers of: serine (2-amino-3-hydroxypropionic acid) cysteine (2-amino-3-mercaptopropionic acid) 3-methoxy-2-methylpropanol 3-bromo-2-methyl-3-propylheptane 2-bromo-2-chloro-1-iodopropane 3-(N,N-dimethylamino)butanal 14.......

Words: 356 - Pages: 2

Fractional Distillation

...mixture of cyclohexane and toluene were separate from one another by fractional distillation in order to measure the composition of each fraction and prepare the sample for gas chromatography. Introduction: Distillation has been used since antiquity to separate the components of mixtures. This method has been used to manufacture different organic chemicals but the most recent application is the refining of petroleum in order to produce fuels, lubricants and petrochemicals. In this experiments, the separation of 2 distilates were carried out using the differences in boiling points and the data was used for a gas chromatography test. Objectives: Separation of an equimolar mixture of cyclohexane and toluene by fractional distillation Materials: Equimolar mixture: cyclohexane/toluene Water Distilling columns Column packing Thermometer heat source flasks heat source Structural Formulas: toluene Description: The fractional distillation apparatus was checked for any moisture before it was set up to ensure proper distillation method. A mixture of cyclohexane and toluene was obtained, 40ml of an equimolar mixture was obtained and transferred into a 100ml round bottomed boiling flask which contained boiling chips, and the distilling column was packed with metal sponge. The distillation apparatus was assembled and a heat mantle was set and several vials were used as fraction receivers and labeled 1-5. The......

Words: 1466 - Pages: 6

Absorption Spectra of Conjugated Dyes

...7 (p+3+α)2p+4 (4) where l=0.139 pm and α is a constant for a series of dyes.3 Experimental: The following polymethines were dissolved in methanol and the diphenyls were dissolved in cyclohexane to give dilute solutions: 1,1’-diethyl-2,2’-cyanine iodide, 1,1’-diethyl-2,2’-carbocyanine chloride, 1,1’-diethyl-2,2’-dicarbocyanine iodide, 1,4-diphenyl-1,3-butadiene, 1,6-diphenyl-1,3,5-hexatriene, and 1,8-diphenyl-1,3,5,7-octatetraene. The concentrations of 1,1’-diethyl-2,2’-cyanine iodide, 1,1’-diethyl-2,2’-carbocyanine chloride, 1,1’-diethyl-2,2’-dicarbocyanine iodide were 1.00 × 10-6 M, 5.02 × 10-7 M and 1.00 × 10-6 M, respectively and were made together by Groups B, C, and D. The concentrations of 1,4-diphenyl-1,3-butadiene, 1,6-diphenyl-1,3,5-hexatriene, and 1,8-diphenyl-1,3,5,7-octatetraene were 5.30 × 10-6 M, 5.20 × 10-6 M, and 5.00 × 10-6 M, respectively and were made by Group A. Each solution was made dilute enough to be perceived accurately with a smooth maximum absorbance below 1 Au. Shown in Figure 1 and Figure 2, absorbances were taken between 190 and 1100 nm for the polymethine dyes and between 330 and 425 nm using an Agilent 8435 UV-Vis Spectrophotometer with disposable plastic cuvettes and methanol and cyclohexane as the blanks. Raw Data: Table 1. Experimental and theoretical wavelengths for 1,1’-diethyl-2,2’-cyanine iodide, 1,1’-diethyl-2,2’-carbocyanine chloride, 1,1’-diethyl-2,2’-dicarbocyanine iodide,......

Words: 2448 - Pages: 10

Organic Chem Lab 1

...Introduction A Diels-Alder reaction is a reaction in which a conjugated diene bonds with an alkane to produce a cyclohexane molecule. This reaction works best with dienes that are electron rich and dienophiles that are electron poor. For this experiment, our dicyclopentadiene is the diene and the maleic acid is our dienophile. In a Diels-Alder reaction, sigma bonds are formed from pi bonds. For this particular experiment, cyclopentadiene and maleic anhydride react via Diels-Alder in order to produce an endo-bicyclic product: cis-5-norbornene-endo-2,3-dicarboxylic anhydride. This product is a six-membered ring alkene with two sigma bonds. Materials and Methods Materials Used * 3 g maleic anhydride * 5 mL dicyclopentadiene * 8 mL ethyl acetate * 3 mL cyclopentadiene (from distillation) Method 1) A total of ____________ of maleic anhydride was measured out into a 125 mL Erlenmeyer flask 2) Approximately ____________ of ethyl acetate was measured out to dissolve the anhydride. This mixture was then placed on a hot plate. 3) Once heated, ____________ of hexanes was added to the mixture, and then allowed to cool in an ice bath. 4) A total of ____________ of distilled, dry cyclopentadiene was then added and mixed with the ice-cold maleic anhydride solution. 5) The mixture was then swirled in the ice bath until the exothermic reaction ended and we saw a white solid precipitate. 6) Recrystallization was then carried out to......

Words: 641 - Pages: 3

Colligative Properties: Freezing Pointdepression and Molar Mass

...adding 250ml of water to dissolve it and the adding it to a beaker 2/3 full with ice. In a nested test tube 10 ml of cyclohexane was measured using a burette in a fume cupboard and the mass of the cyclohexane was calculated, given the density of the cyclohexane to be 0.7726g/mL In the cyclohexane a thermometer ranging between -10 and +110 ℃ was placed in the cyclohexane together with a stirrer around the thermometer, stirring at a rate of 1 stroke per second. The nested apparatus was lowered into the salt /water /ice bath and was gentle stirred until crystals formed at the bottom of the test tube. After the crystals had formed the test tube assembly it was raised out of the salt /water /ice bath temperature readings were made at 30 second interval and they were recorded until the temperature reached about 15℃ . The assembly was placed back into the ice bath and the same readings were taken again at the same time interval. B. DETERMINATION OF THE MOLAR MASS OF AN UNKNOWN Using weighing paper 0.40g of the unknown were was weighed and was added to the cyclohexane test tube and was gentle stirred until all of the unknown had dissolved. It was then put in the ice bath again until some crystals formed at the bottom of the test tube. It was again removed from the ice bath and temperature readings were again taken and recorded twice doing as it was done to the pure cyclohexane. RESULTS: PART A TIME (sec) | TEMPERATURE(oC) 1st reading | TEMPERATURE(oC)2nd reading | 0 | 27 |......

Words: 1635 - Pages: 7

Science

...spectrometry as veraldehyde has a RMM of 86.152 while crotonaldehyde has a mass of 70.090. The mass spectrums obtained would be completely different and based on the mass of the molecular ion, the two aldehydes could be identified. Question 5 Using the laboratory tests identified in this exercise, show how you could distinguish between the following compounds (Hint: use tests that would give a clear, positive test result for a listed compound that is unique to it and thus different from the others): Test | Cyclohexane | Cyclohexanone | Hexanal |  2,4-dinitrophenylhydrazine (DNP)React with 2,4-DNP in the presence of an alcohol and H2SO4 Tollens reagentReact with Tollens reagent(ammonical silver nitrate) | No visible reaction. | A bright red precipitate would be formed.No visible reaction | A bright red precipitate would be formed.A silver mirror would form on the sides of the test tube |   In the reaction with 2,4-DPN it would allow for cyclohexane to be identified as it would be the only compound that did not produce a red precipitate. In the reaction with Tollens reagent, hexanol would form a silver precipitate on the walls of the test tube while cyclohexanone would not as ketones are resistant to oxidation. References: John, K, & Seley, J (2007) Organic Chemistry( 7th edition) Belmont, CA: Johnson Gayle/ Phillips...

Words: 1266 - Pages: 6

Alicyclic Compounds

...ring.  • These deviations of bond angle from the “normal”  geometry  tetrahedral value cause the molecule to be strained, & hence to be  unstable when compared with the molecules in which the bond angles  are tetrahedral.  • Cyclopropane & cyclobutane undergo ring‐opening reactions since they  relive the strain & yield more stable open‐ chain reactions.  • Cyclopropane is more highly strained, more unstable,& more prone to  undergo ring opening reactions than cyclo butane.  • The angles of a regular pentagon(1080) are very close to the tetrahedral angle(109.50).  • The angles of a regular hexagon(1200), are some what larger than tetrahedral angle.  • Baeyer incorrectl proposed there should be a certain amount of strain in cyclohexane &  incorrectly suggested as 1 proceeded to cyclo heptane, cyclo octane, etc……  • The deviation of the bond angles from 109.50 would become progressively larger & the   molecules would become progressively more strained.  Thus Baeyer considered that rings smaller or larger than cyclo pentane or cyclo hexane were  unstable, it was because of this instability that the 3&4 membered rings underwent ring  opening reactions, it was because of this instability that the great difficulty had been  encountered in the synthesis of the larger rings.                                                                                          By,                                                                                              G.DEEPA.  ......

Words: 499 - Pages: 2

Membrane Permeability

...repeat the experiment, causing reduced reliability of the results | Conduct the experiment over a longer period of time to allow for more readings and repetition | Inconsistent temperature of water through uncertainty of thermometer and constant changing temperature | Results were affected due to the temperature not being set | Use water baths | The effect of chemicals on membrane permeability in beetroots Chemicals and their pH | Observations | HCl1.00 | Pink pigment has stained the acid, beetroot itself has lost some pigmentation | NaOH13.26 | Beetroot has turned yellow, NaOH also stained yellow | Cyclohexane6.92 | Beetroot has lost its color (turned grey), secreted purple liquid resting at bottom of test tube, volume of cyclohexane decreased significantly | Acetone8.10 | Beetroot has been eaten and turned brown, secreted orange liquid staining the acetone, volume of acetone decreased by almost half | Ethane6.57 | Volume decreased slightly, beetroot turned red and stained the ethane red |...

Words: 528 - Pages: 3

Adipic Acid

...ABSTRACT Nylons comes in many types but the most common and widely used in textile and plastic industries are Nylon 6 and Nylon 6,6. Nylon 6,6 is made up of two monomers each containing 6 carbon atoms. One of them is Adipic Acid which is a dicarboxylic acid. It is manufactured by oxidation of Cyclohexanol which is produced by oxidative cleavage of cyclohexane or by hydrogenation of phenol. Commercially Cyclohexane is preferred as raw material because of its lower cost and a two-step mechanism involving Nitric acid is used to produce Adipic Acid. This process has higher selectivity and yield than other processes. The only concern with this process is the emission of nitrogen oxides in the gas effluents which is a major environmental concern. 1. Introduction Adipic acid is an organic compound, with formula HOOC (CH2)4COOH, which is a white crystalline solid and one of the most important Dicarboxylic acid. It is Odorless, Colorless and freely soluble in Ethanol, Methanol and Acetone. Other Important properties of Adipic acid is shown in Table 1.From Industrial perspective it is used mainly in Nylon-6, 6 production. About 2.5 billion kilograms of this white crystalline powder are produced annually. In US it is mainly produced by three companies at four manufacturing plants, with nearly two-thirds of the total production, 860,000 tons capacity occurring at DuPont's two Texas facilities. The use of adipic acid in food items have started in recent times and this has created a......

Words: 2104 - Pages: 9

Uuuuuuuuuuuuuuuuuuuuuuu

...STEEL WOOL STEEL WOOL STEEL WOOL BEADS BEADS BEADS BEADS Sample 1.4661 1.4615 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 1.4661 First Second Mole......

Words: 472 - Pages: 2

Bok: Whistleblowing and Professional Responsibility

...Large quantities of the glue still continued to flow into the hands of street children, presumably from the supplies of Fuller’s industrial customers.12 In 1994 the company decided to change the chemical formula of its glue to make it less attractive t o children. The toluene in the glue was replaced with the chemical cyclohexane which smells less sweet and is less volatile than toluene, although like toluene it too produces an intoxicating high and has similar toxic effects on the body. However, because it does not evaporate as quickly as toluene, it takes much longer for cyclohexane to produce similar concentrations of fumes. The company also announced that i t would increase the price of its glue by 30 percent to price it further out of the reach of children. Both of these moves, the company said, would discourage use of its glues among street children. However, Dr. Tim Rohrig, a toxicologist, said that he doubted the formula change had led children to stop sniffing Resistol: “I doubt the kids are that sophisticated that they can differentiate by odor. If it can get them high, then they will use it. ... They may have to take more sniffs with cyclohexane than they would with toluene but they still can get the desired intoxication.” In 1995 the company issued a statement claiming that in reality it “neither manufactured nor sold Resistol.” Instead, the company asserted, it was a subsidiary of a subsidiary of the company in Central America that had actually......

Words: 2438 - Pages: 10

Lipid Structures

...
but
it
can
help
you
determine
if
it
is
a
 phospholipid.
 • To
get
the
structure
of
a
phospholipid:
 o take
the
structure
of
a
triacylglyceride


 o remove
one
fatty
acid
 o replace
it
with
a
phosphate
 o Now
you
have
a
phospholipid
 Prostaglandins
(Function:
Regulators
and
signal
molecules)
 Structure:

A
prostanoic
acid
skeleton
 
 • For
structure
all
you
should
know
is
the
structure
of
a
prostanoic
acid
and
that
 the
name
changes
based
on
the
number
of
OH,
C=O,
and
C=C
groups.
 • This
tutorial
is
focused
on
structure,
but
for
prostaglandins
there
are
a
lot
of
 functions
that
are
important
and
I
recommend
you
know
them.
 Steroid
(Function:
Each
steroid
has
a
variety
of
functions)
 Structure:
A
ring
system
of
three
adjacent
cyclohexanes
and
a
cyclopentane.
 
 • This
ring
system
is
approximately
flat
while
the
other
components
are
not
limited
 to
being
flat
or
not.
 • To
understand
the
structure
of
steroid,
one
must
look
at
the
steps
of
steroid
 biosynthesis.
Specifically
we
are
going
to
observe
the
process
of
changing
acetyl
 CoA
to
chlosterol.
 

 
 Lipophilic
Vitamins
(Functions:
Broad
range
of
functions)
 Structure:
Broad
range
of
structures
 • There
are
a
broad
range
of
structures
for
lipophilic
vitamins,
but
we
only
go
into
 three
vitamins:
Vitamin
E,
Vitamin
C,
and
Vitamin
A.
 • Just
familiarize
yourself
with
these
structures.
 •......

Words: 691 - Pages: 3

Form 6 Chemistry Experiment

... Experiment : Title : Introduction : 7 Estimation of strength of hydrogen bond Breaking or formation of intermolecular hydrogen bonds between molecules in liquids would cause an enthalpy change when the liquids are mixed. This experiment is to investigate such enthalpy changes and to measure approximate strengths of hydrogen bonds formed between molecules of ethanol and those between molecules of trichloromethane and ethyl ethanoate using simple calorimetric methods. Ethanol, cyclohexane, ethyl ethanoate, trichloromethane 10 cm3 and 25 cm3 measuring cylinders, 50 cm3 beaker, 250 cm3 beaker, -10 – 110 °C thermometer, cotton wool [Hazard Warning: Ethanol, cyclohexane and ethyl ethanoate are flammable, trichloromethane is harmful, and tetrachloromethane is toxic.] A. To measure the strength of hydrogen bond formed between ethanol molecules 1. 2. 3. Using a measuring cylinder, add 5 cm3 of ethanol into an insulated 50 cm3 beaker. Measure the temperature of the liquid. Then add 20 cm3 of cyclohexane to the ethanol in the beaker, mix well and record the lowest temperature attained. From the temperature drop estimate the hydrogen bond strength (in kJmol-1) in ethanol. Chemicals : Apparatus : Procedure : B. To measure the strength of hydrogen bonds formed between molecules of ethyl ethanoate and trichloromethane [Hazard Warning: Mixtures of trichloromethane and propanone have been known to explode on standing. The solvent residues from this experiment should not be......

Words: 8885 - Pages: 36