Ultraviolet (UV) radiation and microwaves can be used to initiate organic reactions. UV radiation provides enough energy to homolytically cleave bonds and generate free radicals to propagate reactions. Microwaves are used for heating through interactions with polar molecules. Mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, chromatography, and chemical tests are techniques used to analyze organic compounds and determine molecular structure.
Gas chromatography-mass spectrometry (GC-MS) is a hyphenated technique that combines gas chromatography and mass spectrometry. GC is used to separate compounds in a mixture, while MS identifies the compounds based on their mass-to-charge ratios. The document discusses the basic principles, instrumentation, and applications of GC-MS. It explains how the gas chromatograph separates compounds and the mass spectrometer ionizes and detects them, providing both separation and identification capabilities in a single technique.
Mass spectrometry works by ionizing molecule samples and then sorting the resulting ions based on their mass-to-charge ratio. Samples are bombarded with electrons which causes ionization, and the ions are then accelerated and deflected according to their mass. This provides information about molecular weights, elemental compositions, and structural characteristics that can be used to identify unknown compounds. Common ionization methods include electron impact, chemical ionization, and matrix-assisted laser desorption/ionization. Ions are typically analyzed using quadrupole mass filters or magnetic sectors before being detected.
This presentation discusses various ionization techniques used in mass spectrometry. It begins with an introduction to the history and basic principles of mass spectrometry. It then describes several ionization methods including electron ionization, chemical ionization, desorption chemical ionization, field desorption, fast atom bombardment, and matrix-assisted laser desorption ionization. For each technique, it discusses the ionization process, sample introduction methods, advantages, limitations, and applicable mass ranges. The presentation provides an overview of the key ionization techniques used in mass spectrometry and their characteristics.
UV-visible spectroscopy involves using electromagnetic radiation in the ultraviolet-visible spectral region to analyze molecules. It works by exciting electrons within molecules from their ground state to excited states. The position and intensity of absorption peaks in the UV spectrum depend on factors like the type of chromophore, conjugation, solvent, and pH. UV spectroscopy is used to determine molecular weights, identify functional groups and conjugation, quantify concentrations, and characterize aromatic compounds.
This document provides an overview of mass spectrometry principles and instrumentation. It discusses various components of a mass spectrometer including sample handling systems, ion sources like electron impact and chemical ionization, mass analyzers like quadrupole and time-of-flight, and detectors. It also covers the different types of ions produced during fragmentation, common fragmentation patterns and rules, and applications of techniques like GC/MS and LC/MS in fields like proteomics and metabolomics.
This document provides an overview of mass spectrometry principles and instrumentation. It discusses various components of a mass spectrometer including sample handling systems, ion sources like electron impact and chemical ionization, mass analyzers like quadrupole and time-of-flight, and detectors. It also covers the different types of ions produced during fragmentation, common fragmentation patterns and rules, and applications of techniques like GC/MS and LC/MS in fields like proteomics and metabolomics.
This document provides an overview of mass spectrometry. It discusses the basic principles, instrumentation components like the sample handling system, ion sources, mass analyzers and detectors. It describes different types of ions produced including molecular ions, fragment ions and rearrangement ions. Common ionization techniques are discussed like electron impact, chemical ionization, fast atom bombardment and matrix-assisted laser desorption/ionization. Rules of fragmentation and fragmentation patterns are also summarized. Mass spectrometry is a technique used to analyze molecules by generating gas-phase ions that are then separated and detected based on their mass-to-charge ratio.
Gas chromatography-mass spectrometry (GC-MS) is a hyphenated technique that combines gas chromatography and mass spectrometry. GC is used to separate compounds in a mixture, while MS identifies the compounds based on their mass-to-charge ratios. The document discusses the basic principles, instrumentation, and applications of GC-MS. It explains how the gas chromatograph separates compounds and the mass spectrometer ionizes and detects them, providing both separation and identification capabilities in a single technique.
Mass spectrometry works by ionizing molecule samples and then sorting the resulting ions based on their mass-to-charge ratio. Samples are bombarded with electrons which causes ionization, and the ions are then accelerated and deflected according to their mass. This provides information about molecular weights, elemental compositions, and structural characteristics that can be used to identify unknown compounds. Common ionization methods include electron impact, chemical ionization, and matrix-assisted laser desorption/ionization. Ions are typically analyzed using quadrupole mass filters or magnetic sectors before being detected.
This presentation discusses various ionization techniques used in mass spectrometry. It begins with an introduction to the history and basic principles of mass spectrometry. It then describes several ionization methods including electron ionization, chemical ionization, desorption chemical ionization, field desorption, fast atom bombardment, and matrix-assisted laser desorption ionization. For each technique, it discusses the ionization process, sample introduction methods, advantages, limitations, and applicable mass ranges. The presentation provides an overview of the key ionization techniques used in mass spectrometry and their characteristics.
UV-visible spectroscopy involves using electromagnetic radiation in the ultraviolet-visible spectral region to analyze molecules. It works by exciting electrons within molecules from their ground state to excited states. The position and intensity of absorption peaks in the UV spectrum depend on factors like the type of chromophore, conjugation, solvent, and pH. UV spectroscopy is used to determine molecular weights, identify functional groups and conjugation, quantify concentrations, and characterize aromatic compounds.
This document provides an overview of mass spectrometry principles and instrumentation. It discusses various components of a mass spectrometer including sample handling systems, ion sources like electron impact and chemical ionization, mass analyzers like quadrupole and time-of-flight, and detectors. It also covers the different types of ions produced during fragmentation, common fragmentation patterns and rules, and applications of techniques like GC/MS and LC/MS in fields like proteomics and metabolomics.
This document provides an overview of mass spectrometry principles and instrumentation. It discusses various components of a mass spectrometer including sample handling systems, ion sources like electron impact and chemical ionization, mass analyzers like quadrupole and time-of-flight, and detectors. It also covers the different types of ions produced during fragmentation, common fragmentation patterns and rules, and applications of techniques like GC/MS and LC/MS in fields like proteomics and metabolomics.
This document provides an overview of mass spectrometry. It discusses the basic principles, instrumentation components like the sample handling system, ion sources, mass analyzers and detectors. It describes different types of ions produced including molecular ions, fragment ions and rearrangement ions. Common ionization techniques are discussed like electron impact, chemical ionization, fast atom bombardment and matrix-assisted laser desorption/ionization. Rules of fragmentation and fragmentation patterns are also summarized. Mass spectrometry is a technique used to analyze molecules by generating gas-phase ions that are then separated and detected based on their mass-to-charge ratio.
This document provides an overview of mass spectrometry principles and instrumentation. It discusses various components of a mass spectrometer including sample handling systems, ion sources like electron impact and chemical ionization, mass analyzers like quadrupole and time-of-flight, and detectors. It also covers the different types of ions produced during fragmentation, common fragmentation patterns and rules, and applications of techniques like GC/MS and LC/MS in fields like proteomics and metabolomics.
Mass spectrometry and ionization techniquesSurbhi Narang
Mass spectrometry is a technique that identifies chemicals based on their mass and charge. It works by ionizing chemical compounds and separating the resulting ions based on their mass-to-charge ratio. The document discusses the key components and principles of mass spectrometry including various ionization methods, mass analyzers, and applications such as sequencing proteins, determining molecular weights, and drug discovery.
This document discusses various detectors used in gas chromatography including the flame ionization detector, thermal conductivity detector, flame photometric detector, photoionization detector, atomic emission detector, sulfur chemiluminescence detector, nitrogen chemiluminescence detector, and others. For each detector, it provides information on the basic principle of operation, components, applications, and limitations. The document focuses on explaining how each detector is able to detect and measure compounds eluting from the gas chromatography column based on their specific characteristics.
This document provides an overview of infrared (IR) spectroscopy. It discusses the principle behind IR spectroscopy, the different IR regions, molecular vibrations, factors affecting vibrational frequencies, instrumentation components, sampling techniques, and applications. The key points are:
- IR spectroscopy involves absorption of IR radiation which causes vibrational transitions in molecules. It is used to identify functional groups and study molecular structure.
- The different IR regions are the photographic, very near IR, near IR, and far IR regions. Molecular vibrations include stretching and bending modes.
- Factors like coupled vibrations, hydrogen bonding, and electronic effects influence vibrational frequencies. Instrumentation components are the radiation source, monochromators, detectors,
This document discusses UV-visible spectroscopy. It begins by introducing spectroscopy and the different types, including UV, IR, NMR, and mass spectrometry. It then explains the principles of UV light absorption and Beer-Lambert's law. Factors that affect the position and intensity of UV absorption peaks are described, such as chromophores, auxochromes, pH, solvents, and conjugation. Finally, some applications of UV-visible spectroscopy are mentioned, such as determining molecular weight, impurities, concentrations, and characterizing aromatic compounds.
This document discusses various ionization techniques used in mass spectrometry. It begins with an introduction to mass spectrometry and its basic principles. It then describes several ionization sources including gas phase sources like electron impact ionization and chemical ionization, and desorption sources like electrospray ionization, matrix-assisted laser desorption/ionization, and fast atom bombardment. The document proceeds to provide more detailed explanations of specific ionization techniques like electrospray ionization, atmospheric pressure chemical ionization, atmospheric pressure photoionization, matrix-assisted laser desorption ionization, and fast atom bombardment. It concludes with references used in the document.
Introduction and understanding of emission and absorption spectrum, discussion on flame and its characteristics and the types of flame sources used in AAS, a brief discussion of flame emission spectroscopy ,possibly deep discussion of AAS, Interferences involved in AAS and their reasons.
The ppt is divided into five topics within itself trying to understand each topics individually before jumping into AAS
UV-visible spectroscopy involves using electromagnetic radiation to obtain information about atoms and molecules. It is based on electronic excitation of molecules that causes promotion of an electron from a ground state to an excited state. Factors like conjugation, solvents, and pH can affect the position and intensity of UV absorption. Applications of UV spectroscopy include determining molecular weight, identifying impurities, and characterizing aromatic compounds and conjugation.
Mass spectrometry is an analytical technique that ionizes molecules and separates the resulting ions based on their mass-to-charge ratio. It is a powerful qualitative and quantitative technique used to measure a wide range of clinically relevant analytes. Various ionization sources are used depending on the type of sample, including electron ionization, chemical ionization, electrospray ionization, and matrix-assisted laser desorption/ionization. Ions are accelerated into a mass analyzer such as a quadrupole, magnetic sector, or time-of-flight analyzer which separates the ions based on m/z. The detected ions produce a mass spectrum that provides information about molecular structure.
This document provides an overview of UV/Visible spectroscopy. It discusses the basic principles including electromagnetic radiation, absorption, emission and electronic transitions. It describes terms like chromophores and auxochromes that impact absorption. Instrumentation components are explained such as sources, monochromators, sample holders and detectors. Applications include qualitative and quantitative analysis, detection of impurities and isomers. The document is intended to educate about UV/Visible spectroscopy.
The document summarizes liquid chromatography-mass spectrometry (LC-MS), beginning with an introduction to why LC and mass spectrometry are used and how they are coupled. It then describes the basic components and functioning of an LC-MS system, including sample preparation, interfaces that ionize samples for mass analysis, various mass analyzers like quadrupoles and time-of-flight, and detectors. The document provides details on instrumentation, principles, applications and historical developments of LC-MS.
LC/MS is a technique that combines liquid chromatography separation with mass spectrometry detection. It separates compounds in a complex mixture using HPLC and then uses an interface like electrospray ionization to introduce the separated compounds into the mass spectrometer for identification. Common components of an LC/MS system include the HPLC column, ionization source, mass analyzer and detector. It has various applications in areas like pharmaceutical analysis, food safety testing and clinical research due to its high sensitivity and selectivity.
This document discusses spectroscopy and the electromagnetic spectrum. It begins by defining spectroscopy as dealing with emission and absorption spectra from the interaction of matter with electromagnetic radiation. It then outlines the electromagnetic spectrum, from gamma rays to radio waves, and discusses the properties and characteristics of different regions, including X-rays, infrared, ultraviolet, and visible light. The document focuses on the absorption of different wavelengths by molecules, which results in electronic transitions that can be analyzed through spectroscopy techniques. In summary, it provides an overview of spectroscopy and the electromagnetic spectrum, with a focus on analyzing molecular absorption and excitation through different spectral regions.
This document summarizes a seminar presentation on mass spectrometry. It introduces mass spectrometry and its basic principles, instrumentation, ionization techniques, types of ions, fragmentation rules like McLafferty rearrangement. It then discusses applications in environmental monitoring, geochemistry, chemical industry, and biomolecule identification.
This document provides an overview of infrared (IR) spectroscopy. It discusses the principle behind IR spectroscopy, the different modes of molecular vibration, instrumentation including sources, detectors and monochromators. It also covers sample handling techniques, factors that affect vibrational frequencies and applications of IR spectroscopy such as structure elucidation.
Infrared spectroscopy is a technique used to identify chemical functional groups in molecules by detecting the vibrational transitions of bonds between atoms. It works by measuring how infrared radiation is absorbed by a sample based on the vibrational frequencies of the chemical bonds present. The main components of an IR spectrometer are an infrared radiation source, a sample holder, a detector, and a recorder. Factors like electronic effects, hydrogen bonding, and bond angles can affect the vibrational frequencies observed in IR spectra. Infrared spectroscopy has many applications including structure elucidation and identification of organic compounds.
1. Ultraviolet-visible spectroscopy involves using UV or visible light to analyze molecules based on their light absorption properties.
2. Key components of a UV-Vis spectrophotometer include a light source, monochromator, sample chamber, and detector. It works by measuring how much light is absorbed by a sample at different wavelengths.
3. Quantitative analysis uses the Beer-Lambert law, which states absorbance is proportional to concentration, path length, and absorptivity. This allows for determination of concentrations from absorption measurements.
This document provides an overview of mass spectrometry principles and instrumentation. It discusses various components of a mass spectrometer including sample handling systems, ion sources like electron impact and chemical ionization, mass analyzers like quadrupole and time-of-flight, and detectors. It also covers the different types of ions produced during fragmentation, common fragmentation patterns and rules, and applications of techniques like GC/MS and LC/MS in fields like proteomics and metabolomics.
Mass spectrometry and ionization techniquesSurbhi Narang
Mass spectrometry is a technique that identifies chemicals based on their mass and charge. It works by ionizing chemical compounds and separating the resulting ions based on their mass-to-charge ratio. The document discusses the key components and principles of mass spectrometry including various ionization methods, mass analyzers, and applications such as sequencing proteins, determining molecular weights, and drug discovery.
This document discusses various detectors used in gas chromatography including the flame ionization detector, thermal conductivity detector, flame photometric detector, photoionization detector, atomic emission detector, sulfur chemiluminescence detector, nitrogen chemiluminescence detector, and others. For each detector, it provides information on the basic principle of operation, components, applications, and limitations. The document focuses on explaining how each detector is able to detect and measure compounds eluting from the gas chromatography column based on their specific characteristics.
This document provides an overview of infrared (IR) spectroscopy. It discusses the principle behind IR spectroscopy, the different IR regions, molecular vibrations, factors affecting vibrational frequencies, instrumentation components, sampling techniques, and applications. The key points are:
- IR spectroscopy involves absorption of IR radiation which causes vibrational transitions in molecules. It is used to identify functional groups and study molecular structure.
- The different IR regions are the photographic, very near IR, near IR, and far IR regions. Molecular vibrations include stretching and bending modes.
- Factors like coupled vibrations, hydrogen bonding, and electronic effects influence vibrational frequencies. Instrumentation components are the radiation source, monochromators, detectors,
This document discusses UV-visible spectroscopy. It begins by introducing spectroscopy and the different types, including UV, IR, NMR, and mass spectrometry. It then explains the principles of UV light absorption and Beer-Lambert's law. Factors that affect the position and intensity of UV absorption peaks are described, such as chromophores, auxochromes, pH, solvents, and conjugation. Finally, some applications of UV-visible spectroscopy are mentioned, such as determining molecular weight, impurities, concentrations, and characterizing aromatic compounds.
This document discusses various ionization techniques used in mass spectrometry. It begins with an introduction to mass spectrometry and its basic principles. It then describes several ionization sources including gas phase sources like electron impact ionization and chemical ionization, and desorption sources like electrospray ionization, matrix-assisted laser desorption/ionization, and fast atom bombardment. The document proceeds to provide more detailed explanations of specific ionization techniques like electrospray ionization, atmospheric pressure chemical ionization, atmospheric pressure photoionization, matrix-assisted laser desorption ionization, and fast atom bombardment. It concludes with references used in the document.
Introduction and understanding of emission and absorption spectrum, discussion on flame and its characteristics and the types of flame sources used in AAS, a brief discussion of flame emission spectroscopy ,possibly deep discussion of AAS, Interferences involved in AAS and their reasons.
The ppt is divided into five topics within itself trying to understand each topics individually before jumping into AAS
UV-visible spectroscopy involves using electromagnetic radiation to obtain information about atoms and molecules. It is based on electronic excitation of molecules that causes promotion of an electron from a ground state to an excited state. Factors like conjugation, solvents, and pH can affect the position and intensity of UV absorption. Applications of UV spectroscopy include determining molecular weight, identifying impurities, and characterizing aromatic compounds and conjugation.
Mass spectrometry is an analytical technique that ionizes molecules and separates the resulting ions based on their mass-to-charge ratio. It is a powerful qualitative and quantitative technique used to measure a wide range of clinically relevant analytes. Various ionization sources are used depending on the type of sample, including electron ionization, chemical ionization, electrospray ionization, and matrix-assisted laser desorption/ionization. Ions are accelerated into a mass analyzer such as a quadrupole, magnetic sector, or time-of-flight analyzer which separates the ions based on m/z. The detected ions produce a mass spectrum that provides information about molecular structure.
This document provides an overview of UV/Visible spectroscopy. It discusses the basic principles including electromagnetic radiation, absorption, emission and electronic transitions. It describes terms like chromophores and auxochromes that impact absorption. Instrumentation components are explained such as sources, monochromators, sample holders and detectors. Applications include qualitative and quantitative analysis, detection of impurities and isomers. The document is intended to educate about UV/Visible spectroscopy.
The document summarizes liquid chromatography-mass spectrometry (LC-MS), beginning with an introduction to why LC and mass spectrometry are used and how they are coupled. It then describes the basic components and functioning of an LC-MS system, including sample preparation, interfaces that ionize samples for mass analysis, various mass analyzers like quadrupoles and time-of-flight, and detectors. The document provides details on instrumentation, principles, applications and historical developments of LC-MS.
LC/MS is a technique that combines liquid chromatography separation with mass spectrometry detection. It separates compounds in a complex mixture using HPLC and then uses an interface like electrospray ionization to introduce the separated compounds into the mass spectrometer for identification. Common components of an LC/MS system include the HPLC column, ionization source, mass analyzer and detector. It has various applications in areas like pharmaceutical analysis, food safety testing and clinical research due to its high sensitivity and selectivity.
This document discusses spectroscopy and the electromagnetic spectrum. It begins by defining spectroscopy as dealing with emission and absorption spectra from the interaction of matter with electromagnetic radiation. It then outlines the electromagnetic spectrum, from gamma rays to radio waves, and discusses the properties and characteristics of different regions, including X-rays, infrared, ultraviolet, and visible light. The document focuses on the absorption of different wavelengths by molecules, which results in electronic transitions that can be analyzed through spectroscopy techniques. In summary, it provides an overview of spectroscopy and the electromagnetic spectrum, with a focus on analyzing molecular absorption and excitation through different spectral regions.
This document summarizes a seminar presentation on mass spectrometry. It introduces mass spectrometry and its basic principles, instrumentation, ionization techniques, types of ions, fragmentation rules like McLafferty rearrangement. It then discusses applications in environmental monitoring, geochemistry, chemical industry, and biomolecule identification.
This document provides an overview of infrared (IR) spectroscopy. It discusses the principle behind IR spectroscopy, the different modes of molecular vibration, instrumentation including sources, detectors and monochromators. It also covers sample handling techniques, factors that affect vibrational frequencies and applications of IR spectroscopy such as structure elucidation.
Infrared spectroscopy is a technique used to identify chemical functional groups in molecules by detecting the vibrational transitions of bonds between atoms. It works by measuring how infrared radiation is absorbed by a sample based on the vibrational frequencies of the chemical bonds present. The main components of an IR spectrometer are an infrared radiation source, a sample holder, a detector, and a recorder. Factors like electronic effects, hydrogen bonding, and bond angles can affect the vibrational frequencies observed in IR spectra. Infrared spectroscopy has many applications including structure elucidation and identification of organic compounds.
1. Ultraviolet-visible spectroscopy involves using UV or visible light to analyze molecules based on their light absorption properties.
2. Key components of a UV-Vis spectrophotometer include a light source, monochromator, sample chamber, and detector. It works by measuring how much light is absorbed by a sample at different wavelengths.
3. Quantitative analysis uses the Beer-Lambert law, which states absorbance is proportional to concentration, path length, and absorptivity. This allows for determination of concentrations from absorption measurements.
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...Creative-Biolabs
Neutralizing antibodies, pivotal in immune defense, specifically bind and inhibit viral pathogens, thereby playing a crucial role in protecting against and mitigating infectious diseases. In this slide, we will introduce what antibodies and neutralizing antibodies are, the production and regulation of neutralizing antibodies, their mechanisms of action, classification and applications, as well as the challenges they face.
Signatures of wave erosion in Titan’s coastsSérgio Sacani
The shorelines of Titan’s hydrocarbon seas trace flooded erosional landforms such as river valleys; however, it isunclear whether coastal erosion has subsequently altered these shorelines. Spacecraft observations and theo-retical models suggest that wind may cause waves to form on Titan’s seas, potentially driving coastal erosion,but the observational evidence of waves is indirect, and the processes affecting shoreline evolution on Titanremain unknown. No widely accepted framework exists for using shoreline morphology to quantitatively dis-cern coastal erosion mechanisms, even on Earth, where the dominant mechanisms are known. We combinelandscape evolution models with measurements of shoreline shape on Earth to characterize how differentcoastal erosion mechanisms affect shoreline morphology. Applying this framework to Titan, we find that theshorelines of Titan’s seas are most consistent with flooded landscapes that subsequently have been eroded bywaves, rather than a uniform erosional process or no coastal erosion, particularly if wave growth saturates atfetch lengths of tens of kilometers.
Microbial interaction
Microorganisms interacts with each other and can be physically associated with another organisms in a variety of ways.
One organism can be located on the surface of another organism as an ectobiont or located within another organism as endobiont.
Microbial interaction may be positive such as mutualism, proto-cooperation, commensalism or may be negative such as parasitism, predation or competition
Types of microbial interaction
Positive interaction: mutualism, proto-cooperation, commensalism
Negative interaction: Ammensalism (antagonism), parasitism, predation, competition
I. Mutualism:
It is defined as the relationship in which each organism in interaction gets benefits from association. It is an obligatory relationship in which mutualist and host are metabolically dependent on each other.
Mutualistic relationship is very specific where one member of association cannot be replaced by another species.
Mutualism require close physical contact between interacting organisms.
Relationship of mutualism allows organisms to exist in habitat that could not occupied by either species alone.
Mutualistic relationship between organisms allows them to act as a single organism.
Examples of mutualism:
i. Lichens:
Lichens are excellent example of mutualism.
They are the association of specific fungi and certain genus of algae. In lichen, fungal partner is called mycobiont and algal partner is called
II. Syntrophism:
It is an association in which the growth of one organism either depends on or improved by the substrate provided by another organism.
In syntrophism both organism in association gets benefits.
Compound A
Utilized by population 1
Compound B
Utilized by population 2
Compound C
utilized by both Population 1+2
Products
In this theoretical example of syntrophism, population 1 is able to utilize and metabolize compound A, forming compound B but cannot metabolize beyond compound B without co-operation of population 2. Population 2is unable to utilize compound A but it can metabolize compound B forming compound C. Then both population 1 and 2 are able to carry out metabolic reaction which leads to formation of end product that neither population could produce alone.
Examples of syntrophism:
i. Methanogenic ecosystem in sludge digester
Methane produced by methanogenic bacteria depends upon interspecies hydrogen transfer by other fermentative bacteria.
Anaerobic fermentative bacteria generate CO2 and H2 utilizing carbohydrates which is then utilized by methanogenic bacteria (Methanobacter) to produce methane.
ii. Lactobacillus arobinosus and Enterococcus faecalis:
In the minimal media, Lactobacillus arobinosus and Enterococcus faecalis are able to grow together but not alone.
The synergistic relationship between E. faecalis and L. arobinosus occurs in which E. faecalis require folic acid
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
PPT on Sustainable Land Management presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
3. UV to initiate reactions
• NAME: Ultraviolet (UV) radiation
• TYPE: Form of electromagnetic radiation
• WAVELENGTH: Wavelength between that of
visible light and x-rays 400nm to 10nm
• USE: Enough energy to split molecules
produce free radicals
• MECHANISM: Homolytic fission each atom
takes one electron from covalent bond
• EXAMPLE: E.g. splitting of chlorine molecule into
2 chlorine free radicals
5. Creation of chlorine free radicals from
CFC’s using UV radiation
• WHERE: In outer edge of atmosphere
• TYPE OF UV: UV from sunlight
• INITIATION STEP: CF3Cl (+ UV) CF3 + Cl.
• DANGER: Ozone broken down by Cl.
needed to protect Earth’s surface from UV
radiation
• PROPAGATION STEPS: Cl. + O3 O2 + ClO.ClO.
+ O3 Cl. + 2O2
6. Microwaves
• TYPE: Form of electromagnetic radiation
• WAVELENGTH: Wavelength between that of infrared and radio
waves 1mm to 1m
• USE: For heating/communications
• WAVELENGTH OF MICOWAVES FOR HEATING: Microwave oven
uses wavelength of 12.24cm
• POLAR BONDS: Polar bond when there are 2 atoms of different
electronegativity's in a covalent bond, causing electrons to be
pulled towards the more electronegative atom
• WATER POLARITY: Oxygen of water more electronegative than
hydrogen so electrons pulled towards oxygen atom polar bonds
• HOW MICROWAVE OVENS WORK: Microwaves pass through food,
causing electromagnetic field; polar molecules try to line up with
electromagnetic field by rotating; polar molecules collide, releasing
heat energy
8. Mass spectrometry
• USE: To find relative molecular mass (Mr)
• IONISATION: Electrons bombard sample molecules,
removing electrons to form ions
• M PEAK: Molecular ion peak is second from last peak
on spectrum
• Mr: Molecular mass of ions = mass/charge of the M
peak
• BASE PEAK: Base peak is the highest peak
• RELATIVE ABUNDANCE: Relative abundance for base
peak set at 100% all other peaks measured as a
percentage of this
9. Molecular ion
• FRAGMENTS: Fragmentation pattern caused
by fragments made by bombardment of
sample with electrons
• FREE RADICALS: Only ions show up on the
mass spectrum free radicals are lost
10. Identification of a molecule using mass
spectrometry
• Mr: Mr = mass/charge of M peak
• STRUCTURAL FORMULA: Fragmentation
pattern used to find structural formula e.g.
determining functional group
• CHECKING: Draw out structural formula found
from fragmentation pattern and work out its
Mr should equal the Mr found using M
peak
13. NMR determining molecular structure
• NAME: Nuclear magnetic resonance (NMR)
spectroscopy
• WHAT: Examines how magnetic fields react when you
put it in a larger, external magnetic field by measuring
absorption of energy
• NUCLEAR SPIN: Any atomic nucleus with odd numbers
of nucleons (protons and neutrons) has nuclear spin
which gives it a weak magnetic field
• PROTON NMR: Hydrogen nuclei are single protons, so
proton NMR can be used to find how many hydrogen
atoms there are in an organic molecule and how
they’re arranged
14. Alignment of protons in an external
magnetic field
• NORMAL PROTON SPIN: Protons normally spin in random
directions so their magnetic fields cancel out
• SPIN WITH STRONG EXTERNAL MAGNETIC FIELD: When a
strong external magnetic field is applied, protons align
themselves either with or against the magnetic field
(aligned or opposing)
• ENERGY OF PROTONS: Aligned protons are at a lower
energy than opposing protons
• RADIO WAVES: When protons absorb radio waves they can
flip to become opposing; opposing protons can emit
electrons to become aligned
• OVERALL EFFECT: More aligned protons, so an overall
absorption of energy
15. Absorptions in different environments
• SHIELDING: Surrounding electrons and other
atoms/groups of atoms shield protons from
the effect of external magnetic fields
• ENVIRONMENT: To be in the same
environment, atoms must be joined to exactly
the same thing
16. Chemical shift
• PEAKS OF NMR: Peaks of NMR spectrum show
frequencies at which protons absorb energy
• TMS: Differences in absorption measured against
standard substance such as tetramethylsilane 12
protons in identical environments so has a single peak
away from most peaks of protons of other molecules
• CHEMICAL SHIFT: Chemical shift is the difference in
absorption of a proton relative to TMS
• CALBIRATION: TMS is given a chemical shift of 0 and
TMS is added to the sample for calibration purposes
17. NMR
• NUMBER OF PROTONS: Area under peak tells you how
many protons in that environment
• MULTIPLETS: Spin-spin coupling multiplets are
multiple peaks that show the number of hydrogen
atoms on the adjacent carbon
• 1 PROTON ON ADJACENT CARBON: Doublet is a peak
split into 2 and shows one proton on adjacent carbons
• 2 PROTONS ON ADJACENT CARBON: Triplet is a peak
split into 3 and shows two protons on adjacent carbons
• 3 PROTONS ON ADJACENT CARBONS: Quartet is a
peak split into 4 and shows three protons on adjacent
carbons
18. Magnetic resonance
• MRI: Magnetic resonance imaging scanners study
internal structures in the body works the same as
NMR spectroscopy
• HOW: Body is irradiated with radio waves, hydrogen
nuclei in water molecules interact with radio waves
and different frequencies absorbed depending on the
type of tissue the water molecules are in
• BUILDING 3D IMAGE: 3D image built by using a
computer to combine series of photos taken when
beam of radio waves is moved down the body
• USE: For cancer treatment, bone/joint treatment and
studies of the brain and cardiovascular system
19. Other uses of NMR
• PHARMACEUTICAL: Monitor composition of
products to make sure they are pure, so drug
is not contaminated
21. Infrared spectroscopy to identify
organic molecules
• HOW: Beam of IR radiation goes through
sample, energy is absorbed by bonds in
molecules, increasing their vibrational energy
• BONDS: Different bonds absorb different
wavelengths
• POSITION OF BONDS: Bonds in different
places within a molecule absorb different
wavelengths
22. IR spectrum of different functional
groups
Functional
group
Where it’s found Frequency/wavelength
Type of
absorption
C-H Most organic molecules 2800-3100 Strong, sharp
O-H Alcohols 3200-3500 Strong, broad
O-H Carboxylic acids 2500-3300 Medium, broad
N-H Amines 3200-3500 Strong, sharp
C=O Carbonyls, carboxylic acids 1680-1750 Strong, sharp
C-O Esters, carboxylic acids 1100-1310 Strong, sharp
C-X Halogenoalkanes 500-1000 Strong, sharp
23. Uses of IR spectroscopy
• CHEMICAL INDUSTRY: Measuring the point
where one functional group changes to another
• POLYMER MANUFACTURE: Degree of
polymerisation measured by recording
absorption at frequency of the double bond in
the monomer
• OXIDATION OF POLYMERS: Absorption at 1700 is
shown when the polymer has been oxidised
25. Separation and identification
• MOBILE PHASE: A liquid or gas in which
molecules can move
• STATIONARY PHASE: A solid, or a liquid held in
a solid, in which the molecules can‘t move
• HOW: Components of mix separate when
mobile phase moves through a stationary
phase
• GC: Gas chromatography
• HPLC: High pressure liquid chromatography
26. Gas chromatography
• STATIONARY PHASE: Viscous liquid such as oil coating the inside of
a coiled tube
• MOBILE PHASE: Unreactive carrier gas e.g. nitrogen
• HOW: Sample injected into heated carrier gas stream as a gas or
liquid, each component absorbs to the stationary phase in different
amounts, the more absorption the longer it takes to pass through
the tube
• RETENTION TIME: The amount of time the mobile phase spends
absorbed in the stationary phase
• DETECTOR: Uses thermal conductivity of gases to draw
chromatogram
• PEAK OF CHROMATOGRAM: Retention time
• AREA UNDER CHROMATOGRAM: Relative amount of each
compound
27. High pressure liquid chromatography
• STATIONARY PHASE: Small particles of solid packed in
a tube e.g. silica bonded to hydrocarbons
• MOBILE PHASE: Polar mixture e.g. methanol and water
• HOW: Sample injected into high pressure stream of
mobile phase, carried through tube as a solution and
analysed by a mass spectrometer
• DETECTOR: Absorption of UV light passed through
sample
• USE: When sample is heat-sensitive, has a high boiling
point
28. Chromatography to check purity of
sample
• GC: Used in chemical industry to check purity
of products in continuous production by
diverting product to GC at regular time
intervals
• HPLC: Used to check cleanliness of equipment
used in drug manufacture as it is a very
sensitive analysis, so even small levels of
impurities and residues are detected
31. Hydrogen bonds
• INTERMOLECULAR: No intermolecular H-bonds as there is
no H-O, H-F or H-N bond
• BOILING POINTS: Lower than equivalent alcohols but
higher than equivalent alkanes
• H-BOND WITH WATER: Polar C=O bond of carbonyls
creates slightly negative O, which forms H-bonds with
slightly positive H atom of water
• DISSOLVING IN WATER: Small carbonyls dissolve because
they form hydrogen bonds, which make up for the breaking
of intermolecular forces; larger carbonyls don’t dissolve
because the energy required to break intermolecular forces
is not compensated for by the formation of H-bonds with
water
32. HCN nucleophilic addition
• NUCLEOPHILE: An electron rich atom that donates
electrons to an electron deficient molecule
• REACTANTS: Carbonyl, potassium cyanide, hydrogen
cyanide
• PRODUCTS: Cyanide ions (catalyst), hydroxynitrile
• 1ST STEP: CN- ion attacks C-atom, and donates a pair of
electrons; electrons from double bond transfer to the
oxygen to make O-
• 2ND STEP: H+ from HCN bonds to O-, to form hydroxynitrile
• SAFETY: HCN is a highly toxic gas so use fume cupboard
• OPTICAL ACTIVITY: Carbonyl group is planar, so if reactant
is chiral, the product will be a racemic mixture
33. Test for carbonyl group
• REAGENT: Brady’s reagent/2,4-
dinitrophenylhydrazine
• CONDITIONS: Dissolved in methanol and conc
sulfuric acid
• POSITIVE RESULT: Bright orange precipitate
• IDENTIFYING THE CARBONYL: precipitate
recrystallized, melting point measured and
compared to table of known melting points
35. Oxidation of aldehydes to carboxylic
acids
• REAGENT: Potassium dichromate (6)
• CONDITIONS: Heated under reflux with dil
sulfuric acid
• POSITIVE RESULT: Orange green
• EQUATION: RCH=O + [O] RC=OOH
36. Reduction of carbonyls
• ALDEHYDES: Form primary alcohols when
reduced
• EQUATION: RCH=O + 2[H] RCH2OH
• KETONES: Form secondary alcohols when
reduced
• EQUATION: RCR’=O + 2[H] RCHR’OH
• REAGENT: LiALH4 (lithium aluminium hydride)
• CONDITIONS: In dry ether
37. Test for methyl carbonyl group
• REAGENT: Iodine
• CONDITIONS: Heated in the presence of alkali
• POSITIVE RESULT: Yellow precipitate of
triiodomethane (CHI3), smell of antiseptic
39. Carboxyls
• CARBOXYL GROUP: -COOH
• FUNCTIONAL GROUP OF CARBOXYLIC ACIDS:
RCOOH
• CARBOXYLIC ACID SUFFIX: -oic acid
• pH: Weak acids; partially dissociate to
carboxylate ions and H+ ions in water
40. Solubility of carboxylic acids
• POLARITY: Carboxylic acids are polar because electrons
are pulled towards the more electronegative O-atoms
• BOILING POINTS: High because the molecules are
polar
• SOLUBILITY: Very soluble in water because they can
form hydrogen bonds with water molecules; solubility
decreases as C-chain length increases because London
forces increase as the number of electrons increase
• DIMERS: Formed when a liquid carboxylic acid
hydrogen bonds to just one other carboxylic acid
molecule; increases size so increases intermolecular
forces and boiling point
41. Formation of carboxylic acids
OXIDATION OF PRIMARY
ALCOHOLS AND ALDEHYDES
• OVERVIEW: Primary alcohol
Aldehyde Carboxylic
acid
• EQUATION: RCH2OH + [O]
RCH=O + [O] RC=OOH
HYDROLYSIS OF NITRILES
• CONDITIONS: Heat under
reflux with dilute
hydrochloric acid, distil off
carboxylic acid
• EQUATION: CH3CN + 2H2O +
HCl CH3C=OOH
42. Formation of salts
• REACTANTS: Aqueous
alkali, carboxylic acid
• PRODUCTS: Salt (-oate),
water
• TYPE OF REACTION:
Neutralisation
• REACTANTS: Carbonate
(CO3
2-) or hydrogen
carbonate (HCO3
-),
carboxylic acid
• PRODUCT: Salt, carbon
dioxide and water
• TYPE OF REACTION:
Neutralisation
45. Formation of esters
• REACTANTS: Carboxylic acid, alcohol, acid
catalyst
• PRODUCTS: Ester, water
• DISTILATION: Reversible reaction so product
distilled off as it is formed
• REMOVING ACID: Product mixed with sodium
carbonate to remove unreacted acid
47. Esters
• ALKYL GROUP: Comes from alcohol
• CARBOXYL GROUP: Comes from carboxylic
acid; given suffix –oate
• EXAMPLE: Methanal + Enthanoic acid
Methyl Ethanoate + Water
48. Hydrolysis of esters
• TYPE: Acid hydrolysis
• REACTANTS: Ester,
water
• PRODUCTS: Carboxylic
acid, alcohol
• CONDITIONS: Heat
under reflux with dil
HCl/sulfuric acid; lots of
water to push
equilibrium right
• TYPE: Base hydrolysis
• REACTANTS: Ester,
dilute alkali
• PRODUCTS: Salt,
alcohol
• CONDITIONS: Heat
under reflux
49. Making soaps
• TYPE: Base hydrolysis
• ALCOHOL: Glycerol
• CARBOXYLIC ACID: Fatty acids
• HOW: Heat fats with sodium hydroxide, to
form glycerol and sodium salts (soap), then
add sodium chloride so soap crusts on surface
of the liquid
50. Transesterification
• WHAT: Swapping the alcohol part of the ester
with another alcohol
• LOW FAT SPREADS: Hydrogenation used to be the
method for producing spreads, but that produces
trans-fats so now transesterification is used to
create spreads from oils
• BIODIESEL: Renewable fuel made from vegetable
oils/animal fats by transesterification of ester
with methanol/ethanol to produce methyl/ethyl
esters
51. Formation of polyesters
• REACTANTS: Dicarboxyl, diol
• PRODUCTS: Polyester, water
• ESTER LINKS: C-O-C
56. Structural isomers
• DEFINITION: Same molecular formula,
different structural formula
• C-CHAIN ISOMERISM: Different lengths of
longest carbon chain due to branching
• POSITIONAL ISOMERISM: Same functional
group, joined to different C-atom
• FUNCTIONAL GROUP ISOMERISM: Different
functional group
57. Stereoisomers
• DEFINITION: Same molecular and structural formula
but different 3D arrangement of atoms
• E/Z ISOMERISM: Priority groups attached to carbons of
C=C on either same side (Z) or opposite side (E); no
rotation around pi-bond at room temperature
• OPTICAL ISOMERISM: Chiral carbon (carbon with four
different groups attached) produces enantiomers,
which rotate the plane of plane-polarised light in
opposite directions
• RACEMIC MIX: Equimolar quantities of each
enantiomer of a chiral compound, so mixture is not
optically active
58. Nucleophilic substitution mechanisms
and optical activity
• SN1: Start with a single, chiral product;
intermediate is planar so nucleophile can
attack from either side; produces both
enantiomers, racemic mix
• SN2: Start with a single, chiral product;
nucleophile attacks from opposite side;
product has opposite optical activity to
reactant
60. Acids and bases
• ACID: Proton-donors by releasing H+ ions when in
aqueous solution
• HYDROXONIUM IONS: H+ ions released combine
with water to form H3O+ ions
• BASE: Proton-acceptors by combining with H+
ions of water
• STRONG ACIDS: Fully dissociate to H+ and A- ions
in aqueous solution
• WEAK ACIDS: Only slightly dissociate to H+ and A-
ions in aqueous solution
61. Conjugate pairs
• CONJUGATE ACID: Base + H+
• CONJUGATE BASE: Acid – H+
• CONJUGATE PAIR: Acid and conjugate
base/Base and conjugate acid
62. Water
• AS ACID: Donates a proton to form hydroxide
ions
• AS BASE: Accepts a proton to form hydroxonium
ions
• DISSOCIATION: Very little dissociation;
equilibrium lies on left
• IONIC PRODUCT OF WATER: Kw = [H+][OH-]
• VALUE OF Kw: At 298K = 1.0x10-14 mol2dm-6
• pKw = -logKw
• VALUE OF pKw: At 298K = 14
68. pH curves
• WHAT: Graph of pH plotted against volume of alkali
added
• EQUIVALENCE POINT: All acid is neutralised, resulting
in large change in pH when alkali is added
• RULE OF 2: Strong acid = pH 1, weak acid = pH 3, strong
alkali = pH 13, weak alkali = pH 11
• POSITION OF EQUIVALENCE POINT: Start from pH 7,
go up 3 for strong alkali, down 3 for strong acid
• BUFFER RANGE: When halfway towards equivalence
point for weak acid, strong alkali titration
69. Indicators
• METHYL ORANGE: Use when there is a strong
acid
• PHENOLPHTHALEIN: Use when there is a
strong alkali
• NO INDICATOR AVAILABLE: When both the
acid and alkali are weak, as there is no sharp
change in pH
• USE EITHER: When strong acid and strong
alkali, as there is a long, sharp change in pH
70. Titration curves to find pKa of a weak
acid
• HALF-EQUIVALENCE POINT: pH = pKa
• Ka = 10-pKa
• [HA]2 = 10-pKa[HA]
72. Buffers
• DEFINITION: Resist changes in pH when small amounts of
acid/alkali are added
• ACIDIC BUFFERS: Made from weak acid and salt; pH of less
than 7
• ALKALINE BUFFERS: Made from weak base and salt
• ADDITION OF ACID: H+ conc increases; equilibrium shifts
left to use up excess H+ by it reacting with the base so pH
stays roughly the same
• ADDITION OF BASE: OH- conc increases; equilibrium shifts
to the right to use up excess OH- by reacting with the acid
so pH stays roughly the same
• TITRATION CURVES: Show buffer action for weak acids and
strong bases at half equivalence point
73. Biological reactions
• ENZYMES: Need a particular pH for them to
act as catalysts otherwise they are denatured
• FOOD PRODUCTS: To prevent changes in pH
caused by bacteria and fungi which lead to the
food deteriorating
76. EQUILIBRIUM
• REVERSIBLE REACTION: Reaction goes both
ways; both the forward and backward
reactions occur
• DYNAMIC EQUILIBRIUM: No change in
concentration of the reactants and products
as both the forward and backward reactions
occur at equal rates
• CONDITIONS FOR DYNAMIC EQUILIBRIUM TO
OCCUR: Closed system, constant temperature
77. Reversible industrial reactions
• HABER PROCESS: Manufacture of ammonia
for use in fertilisers and other N-compounds
• REVERSIBLE STAGE OF HABER PROCESS: N2 +
3H2 2NH3
• CONTACT PROCESS: Manufacture of sulfuric
acid for use in fertilisers, dyes, medicines and
batteries
• REVERSIBLE STAGE IN CONTACT PROCESS:
2SO2 + O2 2SO3
79. Kc
• Kc = [products]no. of mols / [reactants]no. of mols
• TYPE OF EQUILIBRIUM: Only applies for
homogeneous equilibrium
• HETEROGENEOUS EQUILIBRIUM: If
heterogeneous mix of solids and gases or
solids and liquids then leave out the conc of
the solid
• WARNING: Do not use for mix of gases and
liquids
80. Finding equilibrium concs
• INITIAL MOLS: Use values given or take initial mols to
be 1 for reactants
• CHANGE IN MOLS: Work out using level of dissociation
or no. of mols of product formed (whichever is given)
remember to include sign (+ if added, - if lost)
• MOLS AT EQUILIBRIUM: Work out by adding change in
mols to initial mols
• CONC AT EQUILIBRIUM: Divide mols at equilibrium by
volume in dm3 (if volume is given in cm3 then divide by
1000 to get it in dm3) these can be put into Kc
equation
81. Finding concs in equilibrium mixture
using Kc
• SUBSTITUTION: Substitute in all known values
into the Kc equation
• REARRANGE: Rearrange equation so the
subject is the thing(s) you want to find the
concentration of
• STOCHIOMETRY: Use the number of mols of
substances to calculate the concentration of
each thing
83. Partial pressures
• TOTAL PRESSURE: Sum of all partial pressures
(p) of individual gases (both reactants and
products)
• p = mole fraction / total pressure
• MOLE FRACTION = number of mols of
particular gas / total number of mols of gas
84. Kp
• Kp = p(products)no. of mols / p(reactants)no. of mols
• WARNING: Do not use square brackets; these are
not concentrations
• ANOTHER WARNING: For heterogeneous
equilibria, only include gases NOT liquids or gases
• TO CALCULATE: Same process as calculating Kc,
except instead of finding concs at equilibrium,
find partial pressures at equilibrium
86. Total entropy and equilibrium constant
• TOTAL ENTROPY = RlnK
• R: Gas constant, 8.31JK-1mol-1
• K: Use either Kc or Kp
• RELATIONSHIP: K increases as total entropy
increases
87. Size of K and reaction progression
• HIGH K (K>1): Greater concentration of product,
equilibrium lies to the right
• LOW K (K<1): Greater concentration of reactants,
equilibrium lies to the left
• DYNAMIC EQUILIBRIUM: Concentrations of reactants
and products does not change when forward and
backward reactions occur at equal rates; K=0
• COMPLETION: If K > 1010 then reaction goes to
completion
• REACTION DOESN’T OCCUR: If K < 10-10
• REVERSIBLE REACTION: If K is between 10-10 and 1010
88. Effect of temperature of total entropy
• TOTAL ENTROPY = entropy of system +
entropy of surroundings
• ENTROPY OF SURROUNDINGS = - enthalpy
change/temp
• INCREASE TEMP: Magnitude of entropy of
surroundings decreases; if endothermic this
causes total entropy to increase, if exothermic
this causes total entropy to decrease
• DECREASE TEMP: Opposite of increase temp
90. Principle
• PRINCIPLE: When there’s a change in
pressure/temp, the equilibrium will shift to
counteract the change
91. Temperatures effect on Kc and Kp
• PRESSURE: Does not effect Kc or Kp
• CATALYSTS: Do not effect Kc or Kp
• TEMPERATURE: Equilibrium shifts to the
endothermic direction when heat is added;
shifts to the exothermic direction when heat is
lost if equilibrium shifts left then K
decreases, if equilibrium shifts right then K
increases
92. Temperature and pressures effect on
rate of reaction
• INCREASE TEMP: Increases rate because larger
fraction of molecules have above the
activation energy (major effect) and increase
in energy means particles move faster so
collide more (minor effect)
• INCREASE PRESSSURE: Only has an effect is
reactants are gaseous; increase of pressure
pushes particles closer together so there are
more collisions and the rate increases
94. Haber process
• EXOTHERMIC: Temperature used (450 degrees) is
a compromise between rate of reaction, which is
increased by increasing temperature, and high
yield, which is decreased by increasing
temperature
• PRESSURE: High pressure gives high yield and
increases rate but is expensive (200 atm used)
• DYNAMIC EQUILIBRIUM: Reaction never reaches
dynamic equilibrium because reaction does not
take place in a closed system keeps forward
reaction occurring at a fast rate
95. Maximising atom economy
• % ATOM ECONOMY = mass of atoms in product /
mass of atoms in reactants (X 100)
• RECYCLING: Increases atom economy by reusing
unreacted gases reactants recycled in Haber
process as equilibrium means that not all
reactants are used up the first time
• FINDING A DIFFERENT ROUTE OF SYNTHESIS:
Synthesis of Ibuprofen was reduced from 4 stages
to 3 stages, increasing atom economy from 40%
to 77%
96. Control of industrial processes
• TOTAL ENTROPY: Must be positive under the
conditions used for the reaction to occur
• SPEED OF REACTION: Slow rate is not
economical; changes to temp, pressure or
addition of catalyst used to speed up reaction
• ATOM ECONOMY: Kept as high as possible e.g by
recycling reactants, changing conditions to
increase yield
• SAFETY: Need to be considered when high
temps/pressures are used, or if
reactants/products are toxic or flammable
98. Entropy
• DEFINITION: Measure of disorder
• ZERO ENTROPY: Perfectly crystalline solid at 0K in
temperature
• 2ND LAW OF THERMODYNAMICS: Entropy always increases
• TOTAL ENTROPY = entropy of system + entropy of
surroundings
• ENTROPY OF SYSTEM = entropy of products – entropy of
reactants (values found in data book)
• ENTROPY OF SURROUNDINGS = -enthalpy change/temp(K)
• UNITS: JK-1mol-1
99. Factors affecting entropy
• PHYSICAL STATE: Entropy of solid < entropy of liquid < entropy of
gas particles get further apart, so there are more possibilities for
their position in space
• DISSOLVING: Entropy increases if a solid is dissolved, entropy
decreases if a gas is dissolved, entropy can either increase or
decrease if a liquid is dissolved (see section on dissolving)
• NUMBER OF PARTICLES: More particles means higher entropy
because there are more possibilities for the particles arrangement
in space
• TEMPERATURE: Increase temp increases entropy because it
increases the quanta of energy of particles, so there are more
possible distributions of the particles
• CHANGE OF STATE: Rapid change in entropy because particles move
further apart/closer together
100. Feasibility
• TOTAL ENTROPY: Must increase for a reaction
to be feasible
• INCREASING TEMP: Increases entropy, so can
be used to make a reaction feasible
102. Enthalpies
• ENTHALPY OF SOLUTION: Enthalpy change when
1 mol of solute is dissolved in sufficient solvent to
produce an infinitely dilute solution
• LATTICE ENTHALPY: Enthalpy change when 1 mol
of a solid ionic compound is produced from
gaseous ions that start infinitely far apart
• ENTHALPY OF HYDRATION: Enthalpy change
when 1 mol of aqueous ions is formed from
gaseous ions
• ENTHALPY OF SOLUTION = Sum of enthalpies of
hydration – lattice enthaply
103. Factors affecting lattice enthalpy and
enthalpy of hydration
• CHARGE OF IONS: Larger charge on ions
increases lattice enthalpy/hydration enthalpy
• IONIC RADII: Larger ionic radii decreases
lattice enthalpy/hydration enthalpy
105. Measuring reaction rates
• COLORIMETRY: Measures change in intensity of
colour
• CLOCK REACTIONS: Time taken for a particular
amount of reactant to react//product to be
formed
• MASS CHANGE/VOLUME CHANGE: Used for gas
reactants/products
• TITRIMETRIC ANALYSIS: Measures changes in
conc of reactant/product when one is acid, alkali
or iodine by reacting with a known volume of
standard solution to neutralise
106. Rate equations
• AVERAGE RATE = change in conc/change time
• RATE = k[A]x[B]y
• K = rate constant, constant at a particular
temp
• [A] AND [B] = concs of substances A and B
• X AND Y = partial orders
• OVERALL ORDER = x + y
111. Effect of temp on rate
• TEMP INCREASES: More molecules have
activation energy rate constant increases
rate of reaction increases
• ARRHENIUS EQUATION: Shows relationship
between rate constant and temp in Kelvin
• LOG FORM OF ARRHENIUS = lnk = -Ea/RT + c
• R = gas constant
• FINDING EA: Graph plotted with lnk on y-axis, 1/T
on x-axis gradient = -Ea/R
• EA EQUATION: So Ea = R x -gradient
112. Rate-determining step
• RDS: Slowest step of reaction mechanism
• RATE EQUATION: Molecules involved shown
by rate equation
• PARTIAL ORDERS: Number of mols of
reactants shown by partial orders of rate
equation
113. Nucleophilic substitution SN1
• TYPE OF RX:Tertiary halogenoalkanes
• OVERALL ORDER: First order rate equation
• RDS: C-X bond breaking is rate determining
step
• FAST STEP: C+ being attacked by OH- is fast
step
• RATE = k[RX]
114. Nucleophilic substitution SN2
• TYPE OF RX: Primary halogenalkanes
• OVERALL ORDER: Second order rate equation
• RDS: Single step only rate-determining step
• RATE = k[RX][OH-]
116. Activation energy
• ACTIVATION ENERGY: Minimum energy needed by reactant
particles before products can form
• EXOTHERMIC: Energy produced
• ENDOTHERMIC: Energy required
• CATALYSTS: Provide an alternative reaction pathway,
lowering activation energy
• HOMOGENEOUS CATALYST: In same physical state as
reactants
• HETEROGENEOUS CATALYST: In different state to reactants
• RECYCLING: Catalysts not part of the products of reaction
so can by recovered and reused