Collision theory of Reaction rates

Collision theory of Reaction rates

Collision theory of Reaction rates – According to collision theory, a chemical reaction takes place only by collisions between the reacting molecules. However, not all collisions are effective. – Only a small fraction of the collisions produce a reaction. – The two main conditions for a collision between the reacting …

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Mass Spectrometry : Introduction

Mass spectrometry (MS) provides the molecular weight and valuable information about the molecular formula, using a very small sample. Introduction to Mass Spectrometry – Infrared spectroscopy gives information about the functional groups in a molecule, but it tells little about the size of the molecule or what heteroatoms are present. …

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How to determine the order of reaction?

Determination of the order of reaction – There are at least four different methods to determine the order of reaction as follows: Using integrated rate equations Graphical method Using half-life period The Differential method Ostwald’s Isolation method (1) Using integrated rate equations – The reaction under study is performed by …

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Characteristic Absorptions of Carbonyl Compounds

– In this subject, we will talk about Characteristic Absorptions of Carbonyl Compounds such as Ketones, Aldehydes, Amines, and Acids. Characteristic Absorptions of Carbonyl Compounds – Because it has a large dipole moment, the C=O double bond produces intense infrared stretching absorptions. – Carbonyl groups absorb at frequencies around 1700 …

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Second order reaction

Second order reaction – Let us take a second order reaction of the type 2A ⎯⎯→ products – Suppose the initial concentration of A is a moles liter–1. – If after time t, x moles of A have reacted, the concentration of A is (a – x). – We know …

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Hydrocarbons: Infrared Spectroscopy of Hydrocarbons

Infrared Spectroscopy of Hydrocarbons – Hydrocarbons contain only carbon–carbon bonds and carbon–hydrogen bonds. – An infrared spectrum does not provide enough information to identify a structure conclusively (unless an authentic spectrum is available to compare “fingerprints”), but the absorptions of the carbon-carbon and carbon-hydrogen bonds can indicate the presence of …

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Molecular Vibrations : IR spectrum

– In this subject we talk about Molecular Vibrations as introduction to understand IR spectrum Molecular Vibrations – Before discussing characteristic infrared absorptions, it’s helpful to understand some theory about the vibrational energies of molecules. – The following drawing shows how a covalent bond between two atoms acts like a …

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Molecularity of a reaction

– we will discuss the Molecularity of a reaction and the Differences Between Order and Molecularity. Molecularity of a reaction – Chemical reactions may be classed into two types : (a) Elementary reactions (b) Complex reactions – An elementary reaction is a simple reaction which occurs in a single step. …

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Inorganic Esters – Esters of Inorganic Acids

Esters of Inorganic Acids – In addition to forming esters with carboxylic acids, alcohols form inorganic esters with inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid. – In each type of ester, the alkoxy (-OR) group of the alcohol replaces a hydroxyl group of the acid, with …

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Sulphur system – Phase diagram of Sulphur

The Sulphur system –  Sulphur system is a one-component, four-phase system. – The four phases are: (a) Two solid polymorphic forms : Rhombic Sulphur (SR) Monoclinic Sulphur (SM) (b) Sulphur Liquid (SL) (c) Sulphur Vapour (SV) – All the four phase can be represented by the only chemical individual (sulphur) …

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Esterification of Alcohols

– In this subject we will talk about the Esterification of Alcohols. What are Alcohols? – Alcohols are organic compounds containing hydroxyl (-OH) groups. – They are some of the most common and useful compounds in nature, in industry, and around the house. – The word alcohol is one of …

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Reactions of Diols

Reactions of Diols

Unique Reactions of Diols – Unique Reactions of Diols are: (1) The Pinacol Rearrangement (2) Periodic Acid Cleavage of Glycols (1) The Pinacol Rearrangement – Using our knowledge of alcohol reactions, we can explain results that seem strange at first glance. – The following dehydration is an example of the …

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Reactions of Alcohols with Thionyl Chloride

Reactions of Alcohols with Thionyl Chloride

Reactions of Alcohols with Thionyl Chloride – Reactions of Alcohols with Thionyl Chloride give alkyl chloride. – Thionyl chloride (SOCl2) is often the best reagent for converting an alcohol to an alkyl chloride. – The by-products (gaseous SO2 and HCl) leave the reaction mixture and ensure there can be no …

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Water system, Phase diagram of Water

Water system, one-component system

The Water system – Under normal conditions the Water system is a three-phase, one-component system. – The three phases involved are liquid water, ice, water vapour. – All these phases can be represented by one chemical entity H2O and hence one component of the system. – The number of phases …

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Reaction of Alcohols with Phosphorus Halides

Reaction of Alcohols with Phosphorus Halides

Reaction of Alcohols with Phosphorus Halides – Reaction of Alcohols with Phosphorus Halides gives alkyl halides. – Several phosphorus halides are useful for converting alcohols to alkyl halides. – Phosphorus tribromide, phosphorus trichloride, and phosphorus pentachloride work well and are commercially available. 3 R-OH + PCl3 → 3 R-Cl + …

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Polymorphism – Allotropy

Polymorphism - Determination of transtion point

Polymorphism – The occurrence of the same substance in more than one crystalline forms is known as Polymorphism. – Polymorphism phenomenon is shown by both elements and compounds. In the case of elements the term allotropy is often used. – The individual crystalline forms of an element are referred to …

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