Alkanes can be prepared through several methods including hydrogenation of alkenes/alkynes, reduction of alkyl halides, decarboxylation of carboxylic acids, hydrolysis of Grignard reagents, and Wurtz, Corey-House, and Kolbe syntheses. Alkanes are nonpolar, colorless liquids or solids that are stable under normal conditions but undergo substitution and thermal/catalytic reactions. Substitution reactions include halogenation, nitration, and sulfonation, while thermal reactions include combustion, pyrolysis, isomerization, and aromatization.
This is a report about Aldehydes. The content of this slideshow are as follows: What is an aldehyde, How to name aldehydes with IUPAC Nomenclature and Common Names, The Physical Properties of Aldehydes, and the examples of aldehyde and its uses. The main objective of this report is to widen the knowledge of the readers/learners concerning of the stated topic so that they can further understand the concept of aldehydes.
Report made by: Students of Sogod National High School STEM 9-Newton
Kyla Krystelle Salva
Krishia Belle Cambalon
Marycris Felicilda
Introduction to Alcohols.
1. What are Alcohols ?
2. Functional Group
3. Classification
4. Monoatomic, diatomic alcohols
5. Monohydric, dihydric alcohols
6. Nomenclature of Alcohols
This is a report about Aldehydes. The content of this slideshow are as follows: What is an aldehyde, How to name aldehydes with IUPAC Nomenclature and Common Names, The Physical Properties of Aldehydes, and the examples of aldehyde and its uses. The main objective of this report is to widen the knowledge of the readers/learners concerning of the stated topic so that they can further understand the concept of aldehydes.
Report made by: Students of Sogod National High School STEM 9-Newton
Kyla Krystelle Salva
Krishia Belle Cambalon
Marycris Felicilda
Introduction to Alcohols.
1. What are Alcohols ?
2. Functional Group
3. Classification
4. Monoatomic, diatomic alcohols
5. Monohydric, dihydric alcohols
6. Nomenclature of Alcohols
Here's a sample self-introduction for a pageant that incorporates a saying:
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Remember to practice your introduction beforehand to ensure a smooth and confident delivery.
* https://www.lobels.com/
* https://thedickinsonian.com/life-style/2015/12/03/a-peek-inside-dickinsons-sororities-kappa-alpha-theta/
Thank you for this incredible opportunity.
Semester - I C) Aliphatic Hydrocarbons by Dr Pramod R Padolepramod padole
C) Aliphatic Hydrocarbons:
a) Alkanes: Methods of formation: i) Wurtz reaction &
ii) Corey-House reaction. Chemical reactions: i) Halogenation (With mechanism), ii) Aromatisation.
b) Alkenes: Methods of formation (With mechanism): i) Dehydrohalogenation of alkyl halides (E1 & E2), ii) Dehydration of alcohols. Chemical reactions: Electrophilic & free radical addition of HX and X2 (With mechanism).
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
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2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Biological screening of herbal drugs: Introduction and Need for
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Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
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Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
How to Make a Field invisible in Odoo 17Celine George
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The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. Preparation Methods
1. Hydrogenation of alkenes or alkynes
2. Reduction of alkyl halides
3. Decarboxylation of carboxylic acid
4. Hydrolysis of Grignard reagents
5. Wurtz synthesis
6. Corey-House alkane synthesis
7. Kolbe’s synthesis
3. Hydrogenation of alkenes or alkynes
Alkenes or alkynes react with hydrogen in the presence of nickel
catalyst at 200-300°C to form alkanes. Other catalyst includes platinum
and palladium.
4.
5. 2. Reduction of Alkyl Halides
Alkyl halides undergo reduction with nascent hydrogen to form alkanes
6. 3. Decarboxylation of carboxylic acid
When sodium salt of carboxylic acid is strongly heated with sodalime
(Na0H+Ca0) a molecule of carbon dioxide is split off as carbonate and an
alkane is formed.
7. 4. Hydrolysis of Grignard Reagent
Grignard reagent on treatment with water gives alkane
8. 5. Wurtz Synthesis
Higher alkanes are produced by heating an alkyl halide with sodium
metal in dry ether solution. Two molecules of alkyl halide lose their
halogen atoms as NaX. The net result is the joining of two alkyl groups
to yield a symmetrical alkane (R-R) having even number of carbon
atoms.
9. 6. Corey-House alkane synthesis
Alkyl halide is first converted to lithium dialkylcopper (LiR2Cu), which is
then treated with an alkyl halide to give an alkane.
This method is useful for the preparation of unsymmetrical alkanes.
10.
11. 7. Kolbe’s Synthesis
When a concentrated solution of sodium salt of a carboxylic acid is
electrolyzed, an alkane is formed.
This reaction is only suitable for the preparation of symmetrical
alkanes
12. Physical properties
• First four alkanes i.e., methane, ethane, propane and butane are
gases.
• Next fifteen members are colorless liquids
• Higher alkanes are wax-like solids
• Non-polar in nature, therefore, dissolves in non-polar solvents i.e.,
carbon tetrachloride and benzene, but insoluble in polar solvents
such as water
• Alkanes are less denser (0.7 g/ml) than water (1.0 g/ml)
• The boiling point of n-alkanes increases with increasing molecular
weight in a smooth manner while melting point do not increase in a
regular fashion
13. Chemical Properties
Alkanes are relatively stable to common reagents such as acids, alkalis,
oxidizing agents etc., at room temperature. The relative stability or
inactivity of alkanes is due to the fact that the electronegativities of
carbon (2.60) and hydrogen (2.1) do not differ appreciably. Thus the bond
electrons in C—H are practically equally shared between them and the
bond is almost nonpolar. The C—C bond is completely nonpolar. Therefore,
polar reagents find no reaction sites on alkane molecules. Furthermore,
the C—C and C—H are strong bonds. This explains why alkanes are stable to
acids, alkalis, oxidizing reagents etc., at room temperature.
14. The random collisions between the molecules of potential reactants
(alkanes and reagents) occur but the energies of these collisions
are not sufficient to bring about a chemical reaction. At high
temperatures, however, the energies of collisions are much
frequently powerful enough to 'break and make' bonds.
Thus alkanes undergo most of their reactions through the formation
of the highly reactive 'free radicals' as a result of 'energetic
collisions' between their molecules at high temperature.
Alkanes give only two types of reactions.
(A) Substitution Reactions; and
(B) Thermal and Catalytic Reactions.
15. A. Substitution Reactions
In these reactions, one or more of the H-atoms of alkane are substituted by
either atoms like chlorine and bromine or by certain groups like nitro (—
NO2), sulphuric (—SO3H), etc.
Some of the most common reactions shown by alkanes are given below.
1. Halogenation:
It involves the substitution of H-atoms of alkanes by as many halogen atoms
i.e., by chlorine (chlorination) ; by bromine (bromination) by iodine
(iodination) or by fluorine (fluorination). The order of reactivity of halogens
in this regard is
F2> Cl2 > Br2 > I2
16. (a) Chlorination
Alkanes react with chlorine in the presence of ultraviolet light
or diffused sunlight or at a temperature of 300-400C, yielding
a mixture of products
17. The reaction do not stop at this stage. The remaining three
hydrogen atoms of ethyl chloride can be successfully replaced by
chlorine atoms.
18. 2. Nitration of alkanes
At ordinary temperatures alkanes do not react with nitric acid.
However, when a mixture of an alkane and nitric acid vapors is
heated at 400-500C, one hydrogen atom on the alkane is
substituted by a nitro group (—NO2).
The process is called vapor phase nitration, and yields a class of
compounds called nitroalkanes.
19. With higher alkanes, a mixture of products is obtained, some of
which result from rupturing carbon-carbon bonds.
For example, the nitration of ethane results in a mixture of
nitromethane and nitroethane
20. 4. Sulfonation
This involves the substitution of a hydrogen atom with a –SO3H group.
At ordinary temperatures neither concentrated nor fuming sulfuric acid
reacts with alkanes. However, when alkanes are subjected to prolonged
reaction with fuming H2S04, one hydrogen atom on the alkane is
replaced by the sulfonic acid group (–SO3H).
Where R=C6H13 or larger alkyl group. Lower alkanes such as methane
and ethane do not give this reaction
21. B. Thermal and Catalytic reactions
1. Combustion/Oxidation: When ignited in the presence of sufficient
excess of oxygen, alkanes burn to form carbon dioxide and water. The
combustion of these hydrocarbons is accompanied by the evolution of
large quantities of heat. This is the most important reaction because it
is the major route by which we provide energy for a wide range of
purposes. For example, we make use of it in our homes and factories
when we burn natural gas, kerosene, and other hydrocarbons.
22. 2. Pyrolysis (Cracking)
The decomposition of a compound by heat is called pyrolysis
(Greek, pyro-fire, lysis-loosening).
When alkanes are heated to a high temperature in the absence of
air, pyrolysis or a 'thermal decomposition' occurs. Large alkane
molecules are broken down or cracked to give a mixture of smaller,
lower molecular weight alkanes, alkenes and hydrogen.
Pyrolysis generally requires temperatures in the range 500-800C.
However, in the presence & of a catalyst (finely divided silica-
alumina), reactions can be carried at less high temperatures and
this is called catalytic cracking.
23. Ethane when heated to 500° in the absence of air gives a mixture of
methane, ethylene and hydrogen.
Propane when pyrolysed at 600 gives a mixture of propylene, ethylene,
methane and hydrogen.
24. 3. Isomerization
The molecular rearrangement of one isomer into one or more other
isomers - called isomerisation. Normal alkanes are converted to their
branched -chain isomers in the presence of aluminium chloride and HCl
at 25°C.
25. Similarly other less branched alkanes isomerize to the more
branched ones. Thus,
Isomerization is used to increase the branched chain content of
lower alkanes produced by cracking, because branched chain
alkanes are more valuable in than n-alkanes in motor spirit
26. 4. Aromatization
Alkanes containing six to ten carbon atoms are converted into
benzene and its homologues at high temperature and in the
presence of a catalyst. The process called aromatization takes
place by simultaneous dehydrogenation and cyclization of an
alkane to give the aromatic hydrocarbon containing the same
number of carbon atoms.
27. Thus when n-hexane is passed over Cr205 supported over alumina
at 600°, benzene is produced.