The document is a PowerPoint presentation about organic synthesis that was produced to help students understand selected topics in AS and A2 level Chemistry. It discusses several common functional groups found in organic molecules and various methods for extending carbon chains or converting one functional group to another, such as using haloalkanes, carbonyl compounds, aromatic rings, nucleophilic addition, substitution, alkylation and acylation reactions. It also covers chiral synthesis and the need to produce only one optical isomer for pharmaceuticals.
This document provides information about carbonyl compounds, specifically aldehydes and ketones. It discusses their IUPAC nomenclature, methods of preparation including oxidation of alcohols and oxidative cleavage of alkenes, and physical and chemical properties. The chemical reactions covered include nucleophilic addition, reduction, condensation, and oxidation reactions. Examples of important aldehydes and ketones are also mentioned along with their structures and uses.
The document discusses chemical processes and various unit operations and processes. It provides examples of important industrial chemical reactions like sulfonation, halogenation, nitration, esterification, hydrogenation, oxidation, hydrolysis and polymerization. It explains the reaction mechanisms, conditions, and applications of these processes. The key reactions covered include electrophilic aromatic substitution, addition reactions, oxidation, hydrolysis, and step-growth polymerization. Industrial applications in production of chemicals, polymers, and other materials are also highlighted.
Homogeneous catalysis refers to reactions where the catalyst is in the same phase as the reactants. Common homogeneous catalysts include acids and bases in aqueous solutions. Homogeneous catalysts can provide selectivity in terms of chemoselectivity, regioselectivity, diastereoselectivity, and enantioselectivity. Important reaction types for homogeneous catalysis include oxidative addition, reductive elimination, migratory insertion, and β-hydride elimination. Key reactions discussed are hydrogenation, hydroformylation, hydrocyanation, and applications of Ziegler-Natta catalysts and Wilkinson's catalyst. Chiral induction with chiral ligands is also discussed for producing chiral molecules in drug synthesis such as L-DOPA
Aldehydes and ketones are organic compounds that contain a carbonyl functional group bonded to at least one hydrogen atom. Common aldehydes include formaldehyde and acetaldehyde. Ketones can be prepared through oxidation of secondary alcohols. Aldehydes and ketones undergo nucleophilic addition reactions that can be base-catalyzed or acid-catalyzed. They have many applications including use in resins, plastics, dyes, preservatives, solvents, drugs, and rubber products.
This document provides information on the topic of homogeneous catalysis. It discusses several types of homogeneous catalysis including hydrogenation, hydroformylation, hydrocyanation, and Wilkinson catalysts. Hydrogenation involves adding hydrogen to organic compounds using molecular hydrogen and a catalyst. Hydroformylation adds a formyl group and hydrogen to an alkene. Hydrocyanation converts alkenes to nitriles. Wilkinson's catalyst is [RhCl(PPh3)3] and is widely used for hydrogenation reactions.
HSSC Second year Chemistry course slides for Federal Board Pakistan, lectures by Dr. Raja Hashim Ali (also available on Youtube as a series of video lectures).
This document provides information about carbonyl compounds, specifically aldehydes and ketones. It discusses their IUPAC nomenclature, methods of preparation including oxidation of alcohols and oxidative cleavage of alkenes, and physical and chemical properties. The chemical reactions covered include nucleophilic addition, reduction, condensation, and oxidation reactions. Examples of important aldehydes and ketones are also mentioned along with their structures and uses.
The document discusses chemical processes and various unit operations and processes. It provides examples of important industrial chemical reactions like sulfonation, halogenation, nitration, esterification, hydrogenation, oxidation, hydrolysis and polymerization. It explains the reaction mechanisms, conditions, and applications of these processes. The key reactions covered include electrophilic aromatic substitution, addition reactions, oxidation, hydrolysis, and step-growth polymerization. Industrial applications in production of chemicals, polymers, and other materials are also highlighted.
Homogeneous catalysis refers to reactions where the catalyst is in the same phase as the reactants. Common homogeneous catalysts include acids and bases in aqueous solutions. Homogeneous catalysts can provide selectivity in terms of chemoselectivity, regioselectivity, diastereoselectivity, and enantioselectivity. Important reaction types for homogeneous catalysis include oxidative addition, reductive elimination, migratory insertion, and β-hydride elimination. Key reactions discussed are hydrogenation, hydroformylation, hydrocyanation, and applications of Ziegler-Natta catalysts and Wilkinson's catalyst. Chiral induction with chiral ligands is also discussed for producing chiral molecules in drug synthesis such as L-DOPA
Aldehydes and ketones are organic compounds that contain a carbonyl functional group bonded to at least one hydrogen atom. Common aldehydes include formaldehyde and acetaldehyde. Ketones can be prepared through oxidation of secondary alcohols. Aldehydes and ketones undergo nucleophilic addition reactions that can be base-catalyzed or acid-catalyzed. They have many applications including use in resins, plastics, dyes, preservatives, solvents, drugs, and rubber products.
This document provides information on the topic of homogeneous catalysis. It discusses several types of homogeneous catalysis including hydrogenation, hydroformylation, hydrocyanation, and Wilkinson catalysts. Hydrogenation involves adding hydrogen to organic compounds using molecular hydrogen and a catalyst. Hydroformylation adds a formyl group and hydrogen to an alkene. Hydrocyanation converts alkenes to nitriles. Wilkinson's catalyst is [RhCl(PPh3)3] and is widely used for hydrogenation reactions.
HSSC Second year Chemistry course slides for Federal Board Pakistan, lectures by Dr. Raja Hashim Ali (also available on Youtube as a series of video lectures).
This document provides an introduction to polymers for A-level chemistry students. It discusses the two main types of polymerization: addition and condensation. Addition polymerization involves monomers joining together with all atoms incorporated into the polymer chain. Condensation polymerization involves monomers joining together with the elimination of small molecules, so not all original atoms are present. Common examples of addition and condensation polymers are discussed, along with their properties and uses.
This document describes the procedure for preparing adipic acid from cyclohexanol via oxidation. Cyclohexanol is oxidized using nitric acid and ammonium metavanadate catalyst at 65-70°C to yield adipic acid crystals. The theoretical and experimental yields and melting point of adipic acid are calculated and measured. Adipic acid is an important industrial dicarboxylic acid used to produce nylon polymers.
The document discusses various types of selectivity in organic reactions including:
- Stereo selectivity which controls the stereochemistry of products
- Regioselectivity which controls the site of reaction
- Chemoselectivity which controls reaction of one functional group in the presence of others
Examples and explanations are provided for each type of selectivity with mechanisms and factors that influence the outcome. Guidelines for solving problems of chemoselectivity involving protecting groups and derivatives that can react only once are also outlined.
This document provides an overview of heterocyclic chemistry. It discusses the classification of aromatic heterocycles based on the number and identity of heteroatoms. Common synthetic strategies for forming heterocycles like the "4+1", "3+3", and "3+2" approaches are presented. Functional group chemistry of heterocycles including imine formation, enols, and enamines is covered. The document summarizes strategies for synthesizing several important bioactive heterocycles like quinolines, isoquinolines, furans, pyrroles, and thiophenes. Examples of the total synthesis of natural products containing these heterocycles are also provided.
The document discusses several examples of homogeneous catalysis including hydrogenation, hydroformylation, hydrocyanation, and Wilkinson's catalyst. It provides details on the mechanisms and applications of these reactions. Homogeneous catalysis refers to reactions where the catalyst is in the same phase as the reactants, usually liquid phase. The catalysts are molecularly dispersed and mass transfer limitations are less of an issue.
This document discusses reduction reactions and reducing agents. It aims to teach the reader to: 1) exploit differences in reactivity between hydride and neutral reducing agents to achieve chemoselective reductions; 2) use substrate chirality to control syn vs. anti diastereoselectivity in ketone reductions; 3) rationalize reaction outcomes using transition state diagrams; 4) appreciate the versatility of transition metals in reductions; 5) understand the utility of dissolving metal reductions; and 6) use radical chemistry for deoxygenation and halide reduction. It then provides details on various hydride and neutral reducing agents, focusing on their reactivities and applications in selective reductions.
This document discusses aldehydes and ketones. It defines them as carbonyl compounds, with aldehydes having a carbonyl bonded to a hydrogen on one side, and ketones having carbonyls bonded to two carbon atoms. It describes their nomenclature and physical properties, such as higher boiling points than hydrocarbons due to polarity. Methods of preparation include oxidation, ozonolysis, and reduction. It also discusses reactions with amines, ylides, and additions. Carboxylic acids and their derivatives are also covered, including nomenclature, acidity, and relative acidities of substituted acids.
Surface Chemistry and its impacts on chemical and electronic industryKramikauniyal
The content thoroughly explains about the processes and phenomenon that occur and are related to the surfaces of substances and how are they so impactful in chemical and electronic industry.
This document summarizes hydroformylation, an industrially important reaction that uses cobalt or rhodium catalysts to produce aliphatic aldehydes from olefins and synthesis gas. It discusses the uses of aldehydes produced via hydroformylation, the homogeneous transition metal catalysts used, including cobalt tetracarbonyl hydride and tris(triphenylphosphine)rhodium carbonyl hydride, the reaction mechanism, and several industrial processes employing cobalt catalysts, such as the BASF-oxo, Exxon, and Shell processes.
This document discusses asymmetric synthesis, which produces unequal amounts of stereoisomers from achiral precursors. It can be enantioselective or diastereoselective. There are two types: partial asymmetric synthesis, which forms a new chiral center from an achiral precursor using a chiral substrate, auxiliary, reagent, or catalyst; and absolute asymmetric synthesis, which uses no chiral precursors but instead relies on physical chirality like circularly polarized light. Common approaches include using a chiral pool substrate, chiral auxiliary, chiral reagent, or chiral catalyst. The mechanisms and examples of various methods are explained in detail.
Carbonyl Compounds (Aldehydes & Ketones) Full ExplanationYo yo Nody khan
Aldehydes and ketones are organic compounds that contain a carbonyl group. Common aldehydes include formaldehyde and acetaldehyde. Ketones have a carbonyl group bonded to two carbon atoms. These compounds can be prepared through oxidation of primary alcohols or secondary alcohols. They undergo characteristic addition reactions that are acid-catalyzed or base-catalyzed. Aldehydes and ketones have many applications, with formaldehyde used in resins and disinfection, and acetone/methyl ethyl ketone used as solvents.
This document provides an overview of catalysis by organometallic compounds. It discusses that organometallic compounds are widely used as homogeneous catalysts in industrial processes and research. Nobel Prizes have been awarded for discoveries in organometallic chemistry and homogeneous catalysis. Examples of important organometallic catalysts discussed include Wilkinson's catalyst, Noyori's catalyst for asymmetric hydrogenation, and Ziegler-Natta catalysts for polymerization of olefins. The mechanisms of homogeneous hydrogenation and different types of catalysis such as homogeneous versus heterogeneous are also summarized.
The document summarizes work done on chiral phosphine-catalyzed asymmetric γ-addition of oxygen nucleophiles to alkynoates. Key findings include: 3-thiophene substituted alkynoate reacted well under standard conditions while other heterocycles did not. Increasing nucleophile loading and slow addition improved yields. Distance of oxygen from aryl group in nucleophile decreased yield and increased ee. Methanol and alkynamide alkynoates gave good yields. Slow addition and altered reaction conditions improved reactivity of problematic substrates. The author thanks advisors and SURF program for the opportunity.
This document summarizes key reactions involving carbonyl compounds, including addition, condensation, and substitution reactions. It discusses the mechanisms of addition reactions involving carbonyl compounds and factors that influence the reactivity. Specific reactions covered include hydration, acetal formation, nucleophilic addition, ester hydrolysis, aminolysis, acylation, aldol condensation, Claisen condensation, Dieckmann condensation, Michael addition, Robinson annulation, and carbonyl substitution reactions.
Carboxylic acids contain the carboxyl group and include common derivatives like acid halides, acid anhydrides, esters, and amides. They are named using IUPAC or common systems and are acidic due to resonance stabilization of the carboxyl group. Carboxylic acids are prepared through oxidation reactions of alkenes, alcohols, aldehydes, and alkyl benzenes or by hydrolysis of nitriles and carbonation of Grignard reagents. Common reactions produce esters, acid halides, anhydrides, and amides. Ibuprofen is a carboxylic acid used as an NSAID with adverse effects including nausea, diarrhea, and headache.
This document presents a study on the uncatalyzed esterification of various aliphatic carboxylic acids with ethanol. Kinetic and thermodynamic parameters were determined for the reactions in an isothermal batch reactor. A second-order reversible kinetic model was developed and used to analyze experimental concentration-time data and determine the kinetic and thermodynamic parameters. The parameters were found to vary for different carboxylic acids and reaction temperatures. The predicted data from the kinetic model agreed reasonably well with the experimental results.
This document provides an introduction to polymers for A-level chemistry students. It discusses the two main types of polymerization: addition and condensation. Addition polymerization involves monomers joining together with all atoms incorporated into the polymer chain. Condensation polymerization involves monomers joining together with the elimination of small molecules, so not all original atoms are present. Common examples of addition and condensation polymers are discussed, along with their properties and uses.
This document describes the procedure for preparing adipic acid from cyclohexanol via oxidation. Cyclohexanol is oxidized using nitric acid and ammonium metavanadate catalyst at 65-70°C to yield adipic acid crystals. The theoretical and experimental yields and melting point of adipic acid are calculated and measured. Adipic acid is an important industrial dicarboxylic acid used to produce nylon polymers.
The document discusses various types of selectivity in organic reactions including:
- Stereo selectivity which controls the stereochemistry of products
- Regioselectivity which controls the site of reaction
- Chemoselectivity which controls reaction of one functional group in the presence of others
Examples and explanations are provided for each type of selectivity with mechanisms and factors that influence the outcome. Guidelines for solving problems of chemoselectivity involving protecting groups and derivatives that can react only once are also outlined.
This document provides an overview of heterocyclic chemistry. It discusses the classification of aromatic heterocycles based on the number and identity of heteroatoms. Common synthetic strategies for forming heterocycles like the "4+1", "3+3", and "3+2" approaches are presented. Functional group chemistry of heterocycles including imine formation, enols, and enamines is covered. The document summarizes strategies for synthesizing several important bioactive heterocycles like quinolines, isoquinolines, furans, pyrroles, and thiophenes. Examples of the total synthesis of natural products containing these heterocycles are also provided.
The document discusses several examples of homogeneous catalysis including hydrogenation, hydroformylation, hydrocyanation, and Wilkinson's catalyst. It provides details on the mechanisms and applications of these reactions. Homogeneous catalysis refers to reactions where the catalyst is in the same phase as the reactants, usually liquid phase. The catalysts are molecularly dispersed and mass transfer limitations are less of an issue.
This document discusses reduction reactions and reducing agents. It aims to teach the reader to: 1) exploit differences in reactivity between hydride and neutral reducing agents to achieve chemoselective reductions; 2) use substrate chirality to control syn vs. anti diastereoselectivity in ketone reductions; 3) rationalize reaction outcomes using transition state diagrams; 4) appreciate the versatility of transition metals in reductions; 5) understand the utility of dissolving metal reductions; and 6) use radical chemistry for deoxygenation and halide reduction. It then provides details on various hydride and neutral reducing agents, focusing on their reactivities and applications in selective reductions.
This document discusses aldehydes and ketones. It defines them as carbonyl compounds, with aldehydes having a carbonyl bonded to a hydrogen on one side, and ketones having carbonyls bonded to two carbon atoms. It describes their nomenclature and physical properties, such as higher boiling points than hydrocarbons due to polarity. Methods of preparation include oxidation, ozonolysis, and reduction. It also discusses reactions with amines, ylides, and additions. Carboxylic acids and their derivatives are also covered, including nomenclature, acidity, and relative acidities of substituted acids.
Surface Chemistry and its impacts on chemical and electronic industryKramikauniyal
The content thoroughly explains about the processes and phenomenon that occur and are related to the surfaces of substances and how are they so impactful in chemical and electronic industry.
This document summarizes hydroformylation, an industrially important reaction that uses cobalt or rhodium catalysts to produce aliphatic aldehydes from olefins and synthesis gas. It discusses the uses of aldehydes produced via hydroformylation, the homogeneous transition metal catalysts used, including cobalt tetracarbonyl hydride and tris(triphenylphosphine)rhodium carbonyl hydride, the reaction mechanism, and several industrial processes employing cobalt catalysts, such as the BASF-oxo, Exxon, and Shell processes.
This document discusses asymmetric synthesis, which produces unequal amounts of stereoisomers from achiral precursors. It can be enantioselective or diastereoselective. There are two types: partial asymmetric synthesis, which forms a new chiral center from an achiral precursor using a chiral substrate, auxiliary, reagent, or catalyst; and absolute asymmetric synthesis, which uses no chiral precursors but instead relies on physical chirality like circularly polarized light. Common approaches include using a chiral pool substrate, chiral auxiliary, chiral reagent, or chiral catalyst. The mechanisms and examples of various methods are explained in detail.
Carbonyl Compounds (Aldehydes & Ketones) Full ExplanationYo yo Nody khan
Aldehydes and ketones are organic compounds that contain a carbonyl group. Common aldehydes include formaldehyde and acetaldehyde. Ketones have a carbonyl group bonded to two carbon atoms. These compounds can be prepared through oxidation of primary alcohols or secondary alcohols. They undergo characteristic addition reactions that are acid-catalyzed or base-catalyzed. Aldehydes and ketones have many applications, with formaldehyde used in resins and disinfection, and acetone/methyl ethyl ketone used as solvents.
This document provides an overview of catalysis by organometallic compounds. It discusses that organometallic compounds are widely used as homogeneous catalysts in industrial processes and research. Nobel Prizes have been awarded for discoveries in organometallic chemistry and homogeneous catalysis. Examples of important organometallic catalysts discussed include Wilkinson's catalyst, Noyori's catalyst for asymmetric hydrogenation, and Ziegler-Natta catalysts for polymerization of olefins. The mechanisms of homogeneous hydrogenation and different types of catalysis such as homogeneous versus heterogeneous are also summarized.
The document summarizes work done on chiral phosphine-catalyzed asymmetric γ-addition of oxygen nucleophiles to alkynoates. Key findings include: 3-thiophene substituted alkynoate reacted well under standard conditions while other heterocycles did not. Increasing nucleophile loading and slow addition improved yields. Distance of oxygen from aryl group in nucleophile decreased yield and increased ee. Methanol and alkynamide alkynoates gave good yields. Slow addition and altered reaction conditions improved reactivity of problematic substrates. The author thanks advisors and SURF program for the opportunity.
This document summarizes key reactions involving carbonyl compounds, including addition, condensation, and substitution reactions. It discusses the mechanisms of addition reactions involving carbonyl compounds and factors that influence the reactivity. Specific reactions covered include hydration, acetal formation, nucleophilic addition, ester hydrolysis, aminolysis, acylation, aldol condensation, Claisen condensation, Dieckmann condensation, Michael addition, Robinson annulation, and carbonyl substitution reactions.
Carboxylic acids contain the carboxyl group and include common derivatives like acid halides, acid anhydrides, esters, and amides. They are named using IUPAC or common systems and are acidic due to resonance stabilization of the carboxyl group. Carboxylic acids are prepared through oxidation reactions of alkenes, alcohols, aldehydes, and alkyl benzenes or by hydrolysis of nitriles and carbonation of Grignard reagents. Common reactions produce esters, acid halides, anhydrides, and amides. Ibuprofen is a carboxylic acid used as an NSAID with adverse effects including nausea, diarrhea, and headache.
This document presents a study on the uncatalyzed esterification of various aliphatic carboxylic acids with ethanol. Kinetic and thermodynamic parameters were determined for the reactions in an isothermal batch reactor. A second-order reversible kinetic model was developed and used to analyze experimental concentration-time data and determine the kinetic and thermodynamic parameters. The parameters were found to vary for different carboxylic acids and reaction temperatures. The predicted data from the kinetic model agreed reasonably well with the experimental results.
Epcon is One of the World's leading Manufacturing Companies.EpconLP
Epcon is One of the World's leading Manufacturing Companies. With over 4000 installations worldwide, EPCON has been pioneering new techniques since 1977 that have become industry standards now. Founded in 1977, Epcon has grown from a one-man operation to a global leader in developing and manufacturing innovative air pollution control technology and industrial heating equipment.
Improving the viability of probiotics by encapsulation methods for developmen...Open Access Research Paper
The popularity of functional foods among scientists and common people has been increasing day by day. Awareness and modernization make the consumer think better regarding food and nutrition. Now a day’s individual knows very well about the relation between food consumption and disease prevalence. Humans have a diversity of microbes in the gut that together form the gut microflora. Probiotics are the health-promoting live microbial cells improve host health through gut and brain connection and fighting against harmful bacteria. Bifidobacterium and Lactobacillus are the two bacterial genera which are considered to be probiotic. These good bacteria are facing challenges of viability. There are so many factors such as sensitivity to heat, pH, acidity, osmotic effect, mechanical shear, chemical components, freezing and storage time as well which affects the viability of probiotics in the dairy food matrix as well as in the gut. Multiple efforts have been done in the past and ongoing in present for these beneficial microbial population stability until their destination in the gut. One of a useful technique known as microencapsulation makes the probiotic effective in the diversified conditions and maintain these microbe’s community to the optimum level for achieving targeted benefits. Dairy products are found to be an ideal vehicle for probiotic incorporation. It has been seen that the encapsulated microbial cells show higher viability than the free cells in different processing and storage conditions as well as against bile salts in the gut. They make the food functional when incorporated, without affecting the product sensory characteristics.
Recycling and Disposal on SWM Raymond Einyu pptxRayLetai1
Increasing urbanization, rural–urban migration, rising standards of living, and rapid development associated with population growth have resulted in increased solid waste generation by industrial, domestic and other activities in Nairobi City. It has been noted in other contexts too that increasing population, changing consumption patterns, economic development, changing income, urbanization and industrialization all contribute to the increased generation of waste.
With the increasing urban population in Kenya, which is estimated to be growing at a rate higher than that of the country’s general population, waste generation and management is already a major challenge. The industrialization and urbanization process in the country, dominated by one major city – Nairobi, which has around four times the population of the next largest urban centre (Mombasa) – has witnessed an exponential increase in the generation of solid waste. It is projected that by 2030, about 50 per cent of the Kenyan population will be urban.
Aim:
A healthy, safe, secure and sustainable solid waste management system fit for a world – class city.
Improve and protect the public health of Nairobi residents and visitors.
Ecological health, diversity and productivity and maximize resource recovery through the participatory approach.
Goals:
Build awareness and capacity for source separation as essential components of sustainable waste management.
Build new environmentally sound infrastructure and systems for safe disposal of residual waste and replacing current dumpsites which should be commissioned.
Current solid waste management situation:
The status.
Solid waste generation rate is at 2240 tones / day
collection efficiently is at about 50%.
Actors i.e. city authorities, CBO’s , private firms and self-disposal
Current SWM Situation in Nairobi City:
Solid waste generation – collection – dumping
Good Practices:
• Separation – recycling – marketing.
• Open dumpsite dandora dump site through public education on source separation of waste, of which the situation can be reversed.
• Nairobi is one of the C40 cities in this respect , various actors in the solid waste management space have adopted a variety of technologies to reduce short lived climate pollutants including source separation , recycling , marketing of the recycled products.
• Through the network, it should expect to benefit from expertise of the different actors in the network in terms of applicable technologies and practices in reducing the short-lived climate pollutants.
Good practices:
Despite the dismal collection of solid waste in Nairobi city, there are practices and activities of informal actors (CBOs, CBO-SACCOs and yard shop operators) and other formal industrial actors on solid waste collection, recycling and waste reduction.
Practices and activities of these actor groups are viewed as innovations with the potential to change the way solid waste is handled.
CHALLENGES:
• Resource Allocation.
Evolving Lifecycles with High Resolution Site Characterization (HRSC) and 3-D...Joshua Orris
The incorporation of a 3DCSM and completion of HRSC provided a tool for enhanced, data-driven, decisions to support a change in remediation closure strategies. Currently, an approved pilot study has been obtained to shut-down the remediation systems (ISCO, P&T) and conduct a hydraulic study under non-pumping conditions. A separate micro-biological bench scale treatability study was competed that yielded positive results for an emerging innovative technology. As a result, a field pilot study has commenced with results expected in nine-twelve months. With the results of the hydraulic study, field pilot studies and an updated risk assessment leading site monitoring optimization cost lifecycle savings upwards of $15MM towards an alternatively evolved best available technology remediation closure strategy.
Microbial characterisation and identification, and potability of River Kuywa ...Open Access Research Paper
Water contamination is one of the major causes of water borne diseases worldwide. In Kenya, approximately 43% of people lack access to potable water due to human contamination. River Kuywa water is currently experiencing contamination due to human activities. Its water is widely used for domestic, agricultural, industrial and recreational purposes. This study aimed at characterizing bacteria and fungi in river Kuywa water. Water samples were randomly collected from four sites of the river: site A (Matisi), site B (Ngwelo), site C (Nzoia water pump) and site D (Chalicha), during the dry season (January-March 2018) and wet season (April-July 2018) and were transported to Maseno University Microbiology and plant pathology laboratory for analysis. The characterization and identification of bacteria and fungi were carried out using standard microbiological techniques. Nine bacterial genera and three fungi were identified from Kuywa river water. Clostridium spp., Staphylococcus spp., Enterobacter spp., Streptococcus spp., E. coli, Klebsiella spp., Shigella spp., Proteus spp. and Salmonella spp. Fungi were Fusarium oxysporum, Aspergillus flavus complex and Penicillium species. Wet season recorded highest bacterial and fungal counts (6.61-7.66 and 3.83-6.75cfu/ml) respectively. The results indicated that the river Kuywa water is polluted and therefore unsafe for human consumption before treatment. It is therefore recommended that the communities to ensure that they boil water especially for drinking.
Kinetic studies on malachite green dye adsorption from aqueous solutions by A...Open Access Research Paper
Water polluted by dyestuffs compounds is a global threat to health and the environment; accordingly, we prepared a green novel sorbent chemical and Physical system from an algae, chitosan and chitosan nanoparticle and impregnated with algae with chitosan nanocomposite for the sorption of Malachite green dye from water. The algae with chitosan nanocomposite by a simple method and used as a recyclable and effective adsorbent for the removal of malachite green dye from aqueous solutions. Algae, chitosan, chitosan nanoparticle and algae with chitosan nanocomposite were characterized using different physicochemical methods. The functional groups and chemical compounds found in algae, chitosan, chitosan algae, chitosan nanoparticle, and chitosan nanoparticle with algae were identified using FTIR, SEM, and TGADTA/DTG techniques. The optimal adsorption conditions, different dosages, pH and Temperature the amount of algae with chitosan nanocomposite were determined. At optimized conditions and the batch equilibrium studies more than 99% of the dye was removed. The adsorption process data matched well kinetics showed that the reaction order for dye varied with pseudo-first order and pseudo-second order. Furthermore, the maximum adsorption capacity of the algae with chitosan nanocomposite toward malachite green dye reached as high as 15.5mg/g, respectively. Finally, multiple times reusing of algae with chitosan nanocomposite and removing dye from a real wastewater has made it a promising and attractive option for further practical applications.
Optimizing Post Remediation Groundwater Performance with Enhanced Microbiolog...Joshua Orris
Results of geophysics and pneumatic injection pilot tests during 2003 – 2007 yielded significant positive results for injection delivery design and contaminant mass treatment, resulting in permanent shut-down of an existing groundwater Pump & Treat system.
Accessible source areas were subsequently removed (2011) by soil excavation and treated with the placement of Emulsified Vegetable Oil EVO and zero-valent iron ZVI to accelerate treatment of impacted groundwater in overburden and weathered fractured bedrock. Post pilot test and post remediation groundwater monitoring has included analyses of CVOCs, organic fatty acids, dissolved gases and QuantArray® -Chlor to quantify key microorganisms (e.g., Dehalococcoides, Dehalobacter, etc.) and functional genes (e.g., vinyl chloride reductase, methane monooxygenase, etc.) to assess potential for reductive dechlorination and aerobic cometabolism of CVOCs.
In 2022, the first commercial application of MetaArray™ was performed at the site. MetaArray™ utilizes statistical analysis, such as principal component analysis and multivariate analysis to provide evidence that reductive dechlorination is active or even that it is slowing. This creates actionable data allowing users to save money by making important site management decisions earlier.
The results of the MetaArray™ analysis’ support vector machine (SVM) identified groundwater monitoring wells with a 80% confidence that were characterized as either Limited for Reductive Decholorination or had a High Reductive Reduction Dechlorination potential. The results of MetaArray™ will be used to further optimize the site’s post remediation monitoring program for monitored natural attenuation.
ENVIRONMENT~ Renewable Energy Sources and their future prospects.tiwarimanvi3129
This presentation is for us to know that how our Environment need Attention for protection of our natural resources which are depleted day by day that's why we need to take time and shift our attention to renewable energy sources instead of non-renewable sources which are better and Eco-friendly for our environment. these renewable energy sources are so helpful for our planet and for every living organism which depends on environment.
Climate Change All over the World .pptxsairaanwer024
Climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. It encompasses both global warming driven by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. While climate change is a natural phenomenon, human activities, particularly since the Industrial Revolution, have accelerated its pace and intensity
2. INTRODUCTION
This Powerpoint show is one of several produced to help students
understand selected topics at AS and A2 level Chemistry. It is based on the
requirements of the AQA and OCR specifications but is suitable for other
examination boards.
Individual students may use the material at home for revision purposes or it
may be used for classroom teaching with an interactive white board.
Accompanying notes on this, and the full range of AS and A2 topics, are
available from the KNOCKHARDY SCIENCE WEBSITE at...
www.knockhardy.org.uk/sci.htm
Navigation is achieved by...
either clicking on the grey arrows at the foot of each page
or using the left and right arrow keys on the keyboard
KNOCKHARDY PUBLISHING
ORGANIC SYNTHESIS
5. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others.
Many industrial processes involve a multi stage process where functional
groups are converted into other functional groups.
6. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others.
Many industrial processes involve a multi stage process where functional
groups are converted into other functional groups.
When planning a synthetic route, chemists must consider...
7. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others.
Many industrial processes involve a multi stage process where functional
groups are converted into other functional groups.
When planning a synthetic route, chemists must consider...
• the reagents required to convert one functional group into another
• the presence of other functional groups - in case also they react
8. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others.
Many industrial processes involve a multi stage process where functional
groups are converted into other functional groups.
When planning a synthetic route, chemists must consider...
• the reagents required to convert one functional group into another
• the presence of other functional groups - in case also they react
• the conditions required - temperature, pressure, catalyst
• the rate of the reaction
• the yield - especially important for equilibrium reactions
• atom economy
9. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others.
Many industrial processes involve a multi stage process where functional
groups are converted into other functional groups.
When planning a synthetic route, chemists must consider...
• the reagents required to convert one functional group into another
• the presence of other functional groups - in case also they react
• the conditions required - temperature, pressure, catalyst
• the rate of the reaction
• the yield - especially important for equilibrium reactions
• atom economy
• safety - toxicity and flammability of reactants and products
• financial economy - cost of chemicals, demand for product
• problems of purification
• possibility of optically active products
10. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others.
Many industrial processes involve a multi stage process where functional
groups are converted into other functional groups.
When planning a synthetic route, chemists must consider...
• the reagents required to convert one functional group into another
• the presence of other functional groups - in case also they react
• the conditions required - temperature, pressure, catalyst
• the rate of the reaction
• the yield - especially important for equilibrium reactions
• atom economy
• safety - toxicity and flammability of reactants and products
• financial economy - cost of chemicals, demand for product
• problems of purification
• possibility of optically active products
11. ORGANIC SYNTHESIS
Functional groups
Common functional groups found in organic molecules include...
alkene
hydroxyl (alcohols)
haloalkane
carbonyl (aldehydes & ketones)
amine
nitrile
carboxylic acid
ester
12. ORGANIC SYNTHESIS
Involves the preparation of new compounds from others, for example…
ESTERS
ALKANES ALKENES
HALOGENOALKANES
ALCOHOLS
AMINES
ALDEHYDES
KETONES
CARBOXYLIC ACIDS
POLYMERS
NITRILES
DIBROMOALKANES
13. EXTENDING A CARBON CHAIN
Rationale
Methods Haloalkanes
Carbonyl compounds (aldehydes and ketones)
Aromatic (benzene) rings
15. POTASSIUM CYANIDE
Reagent Aqueous, alcoholic potassium (or sodium) cyanide
Conditions Reflux in aqueous , alcoholic solution
Product Nitrile (cyanide)
Nucleophile cyanide ion (CN¯)
Equation e.g. C2H5Br + KCN (aq/alc) ——> C2H5CN + KBr(aq)
Mechanism
Importance extends the carbon chain by one carbon atom
the CN group can be converted to carboxylic acids or amines.
Hydrolysis C2H5CN + 2H2O ———> C2H5COOH + NH3
Reduction C2H5CN + 4[H] ———> C2H5CH2NH2
NUCLEOPHILIC SUBSTITUTION
16. CARBONYL COMPOUNDS - NUCLEOPHILIC ADDITION
Reagent potassium cyanide – followed by dilute acid
Conditions reflux
Nucleophile cyanide ion CN¯
Product(s) hydroxynitrile (cyanohydrin)
Equation CH3CHO + HCN ——> CH3CH(OH)CN
2-hydroxypropanenitrile
Notes HCN is a weak acid and has difficulty dissociating into ions
HCN H+ + CN¯
Using ionic KCN produces more of the nucleophilic CN¯
Alternative reagent: HCN catalysed by alkali which shifts
the above equilibrium in favour of CN¯
HIGHLY TOXIC
TAKE GREAT CARE
17. CARBONYL COMPOUNDS - NUCLEOPHILIC ADDITION
Mechanism Nucleophilic addition
Step 1 CN¯ acts as a nucleophile and attacks the slightly positive C
One of the C=O bonds breaks; a pair of electrons goes onto the O
STEP 1
18. CARBONYL COMPOUNDS - NUCLEOPHILIC ADDITION
Mechanism Nucleophilic addition
Step 1 CN¯ acts as a nucleophile and attacks the slightly positive C
One of the C=O bonds breaks; a pair of electrons goes onto the O
Step 2 A pair of electrons is used to form a bond with H+
Overall, there has been addition of HCN
STEP 2
STEP 1
19. CARBONYL COMPOUNDS - NUCLEOPHILIC ADDITION
Mechanism Nucleophilic addition
Step 1 CN¯ acts as a nucleophile and attacks the slightly positive C
One of the C=O bonds breaks; a pair of electrons goes onto the O
Step 2 A pair of electrons is used to form a bond with H+
Overall, there has been addition of HCN
STEP 2
STEP 1
20. CARBONYL COMPOUNDS - NUCLEOPHILIC ADDITION
Mechanism Nucleophilic addition
Step 1 CN¯ acts as a nucleophile and attacks the slightly positive C
One of the C=O bonds breaks; a pair of electrons goes onto the O
Step 2 A pair of electrons is used to form a bond with H+
Overall, there has been addition of HCN
STEP 2
STEP 1
21. FRIEDEL-CRAFTS REACTIONS OF BENZENE - ALKYLATION
Overview Alkylation involves substituting an alkyl (methyl, ethyl) group
Reagents a halogenoalkane (RX) and anhydrous aluminium chloride AlCl3
Conditions room temperature; dry inert solvent (ether)
Electrophile a carbocation ion R+ (e.g. CH3
+)
Equation C6H6 + C2H5Cl ———> C6H5C2H5 + HCl
Mechanism
General A catalyst is used to increase the positive nature of the electrophile
and make it better at attacking benzene rings.
AlCl3 acts as a Lewis Acid and helps break the C—Cl bond.
22. FRIEDEL-CRAFTS REACTIONS OF BENZENE - ACYLATION
Overview Acylation involves substituting an acyl (methanoyl, ethanoyl) group
Reagents an acyl chloride (RCOX) and anhydrous aluminium chloride AlCl3
Conditions reflux 50°C; dry inert solvent (ether)
Electrophile RC+= O ( e.g. CH3C+O )
Equation C6H6 + CH3COCl ———> C6H5COCH3 + HCl
Mechanism
Product A carbonyl compound (aldehyde or ketone)
23. EXTENDING A CARBON CHAIN
Rationale
Methods Haloalkanes
Carbonyl compounds (aldehydes and ketones)
Aromatic (benzene) rings
25. CHIRAL SYNTHESIS
Rationale
Pharmaceutical synthesis often requires the production of just one optical
isomer. This is because...
• one optical isomer usually works better than the other
• the other optical isomer may cause dangerous side effects
• laboratory reactions usually produce both optical isomers
• naturally occurring reactions usually produce just one optical isomer
26. CHIRAL SYNTHESIS
Rationale
Pharmaceutical synthesis often requires the production of just one optical
isomer. This is because...
• one optical isomer usually works better than the other
• the other optical isomer may cause dangerous side effects
• laboratory reactions usually produce both optical isomers
• naturally occurring reactions usually produce just one optical isomer
Example Aldehydes and ketones undergo nucleophilic addition
with cyanide (nitrile) ions;
CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
27. CHIRAL SYNTHESIS
Example
Aldehydes and ketones undergo nucleophilic addition with cyanide ions
CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
28. CHIRAL SYNTHESIS
Example
Aldehydes and ketones undergo nucleophilic addition with cyanide ions
CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
Problem - the C=O bond is planar
- the nucleophile can attack from above and below
- there is an equal chance of each possibility
- a mixture of optically active isomers is produced
- only occurs if different groups are attached to the C=O
29. CHIRAL SYNTHESIS
Example
Aldehydes and ketones undergo nucleophilic addition with cyanide ions
CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
Problem - the C=O bond is planar
- the nucleophile can attack from above and below
- there is an equal chance of each possibility
- a mixture of optically active isomers is produced
- only occurs if different groups are attached to the C=O
CN¯ attacks
from above
30. CHIRAL SYNTHESIS
Example
Aldehydes and ketones undergo nucleophilic addition with cyanide ions
CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
Problem - the C=O bond is planar
- the nucleophile can attack from above and below
- there is an equal chance of each possibility
- a mixture of optically active isomers is produced
- only occurs if different groups are attached to the C=O
CN¯ attacks
from below
31. CHIRAL SYNTHESIS
Example CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
CN¯ attacks
from above
CN¯ attacks
from below
MIRROR
IMAGES
32. CHIRAL SYNTHESIS
Example CH3CHO + HCN ——> CH3CH(OH)CN
ethanal 2-hydroxypropanenitrile
CN¯ attacks
from above
CN¯ attacks
from below
34. CHIRAL SYNTHESIS
Consequences • isomers have to be separated to obtain the effective one
• separation can be expensive and complicated
• non-separation leads to
35. CHIRAL SYNTHESIS
Consequences • isomers have to be separated to obtain the effective one
• separation can be expensive and complicated
• non-separation leads to
larger doses needed
possible dangerous side effects
possible legal action
36. CHIRAL SYNTHESIS
Consequences • isomers have to be separated to obtain the effective one
• separation can be expensive and complicated
• non-separation leads to
larger doses needed
possible dangerous side effects
possible legal action
Solution • use natural chiral molecules as starting materials
• use stereoselective reactions which give one isomer
• use catalysts which give a specific isomer
• use enzymes or bacteria which are stereoselective
37. CHIRAL SYNTHESIS
Consequences • isomers have to be separated to obtain the effective one
• separation can be expensive and complicated
• non-separation leads to
larger doses needed
possible dangerous side effects
possible legal action
Solution • use natural chiral molecules as starting materials
• use stereoselective reactions which give one isomer
• use catalysts which give a specific isomer
• use enzymes or bacteria which are stereoselective
Other examples Nucleophilic substitution of haloalkanes
38. NUCLEOPHILIC SUBSTITUTION
Problems There are two possible mechanisms
SN2
This produces just one optical isomer with reversed optical activity
Called SN2 because two species are involved in the rate determining step.
39. NUCLEOPHILIC SUBSTITUTION
Problems There are two possible mechanisms
SN1
This produces a racemic mixture of two optical isomers
Called SN1 because one species is involved in the rate determining step.
40. NUCLEOPHILIC SUBSTITUTION
Problems There are two possible mechanisms
SN2
This produces just one optical isomer with reversed optical activity
Called SN2 because two species are involved in the rate determining step.
SN1
This produces a racemic mixture of two optical isomers
Called SN1 because one species is involved in the rate determining step.
41. MODERN SYNTHETIC METHODS
The following methods can be used to synthesise a single optical isomer
Enzymes / bacteria
Chiral chemicals
Chiral catalysts
Natural chiral molecules