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What is Analytical Chemistry? Analytical chemistry is what analytical chemists do. – Analytical chemistry is too broad and active a discipline for us to easily or completely define in an introductory textbook. Instead, we will try to say a little about what analytical chemistry is, as well as a little …

– In this topic, we will discuss Acid-Base catalysis: definition, Examples and Mechanism. Acid-Base catalysis – A number of homogeneous catalytic reactions are known which are catalysed by acids or bases, or both acids and bases.  These are often referred to as Acid-Base catalysts. – Arrhenius pointed out that acid …

What happens in an NMR spectrometer? – Before discussing the design of spectrometers, let’s review what happens in an NMR spectrometer. – Protons (in the sample compound) are placed in a magnetic field, where they align either with the field or against it. – While still in the magnetic field, …

– In this topic, we will discuss the Magnetic Shielding by Electrons Magnetic Shielding by Electrons – Up to now, we have considered the resonance of a naked proton in a magnetic field, but real protons in organic compounds are not naked. – They are surrounded by electrons that partially …

Theories of Catalysis – There are two main theories of catalysis: (1) Intermediate Compound Formation theory. (2) The Adsorption theory. – In general, the Intermediate Compound Formation theory applies to homogeneous catalytic reactions and the Adsorption theory applies to heterogeneous catalytic reactions. The Intermediate Compound Formation Theory – The Intermediate …

– In this topic, we will discuss Autocatalysis, Catalytic poisoning and Negative Catalysis. Catalytic poisoning – Very often a heterogeneous catalyst in rendered ineffective by the presence of small amounts of impurities in the reactants. – A substance which destroys the activity of the catalyst to accelerate a reaction, is …

Introduction to NMR  – Nuclear magnetic resonance spectroscopy (NMR) is the most powerful tool available for organic structure determination. – Like infrared spectroscopy, NMR can be used with a very small sample, and it does not harm the  sample. – The NMR spectrum provides a great deal of information about …

– In this topic, we will discuss general Characteristics of Catalytic Reactions and Promoters. General Characteristics of Catalytic Reactions – Although there are different types of catalytic reactions, the following features or characteristics are common to most of them. (1) A catalyst remains unchanged in mass and chemical composition at …

– In this topic, we will discuss the Fragmentation Patterns in Mass Spectrometry. Fragmentation Patterns in Mass Spectrometry – In addition to the molecular formula, the mass spectrum provides structural information. – An electron with a typical energy of 70 eV (6740 kJ mol or 1610 kcal mol) has far …

– In this topic, we will discuss the Catalysis and The types of catalysis : Homogeneous catalysis – Heterogenous catalysis. What is Catalysis? – Berzelius (1836) realised that there are substances which increase the rate of a reaction without themselves being consumed. – He believed that the function of such …

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 …

Determination of the Molecular Formula by Mass Spectrometry – we can Determine the Molecular Formula by Mass Spectrometry and we will discuss : (A) High-Resolution Mass Spectrometry (B) Use of Heavier Isotope Peaks (A) High-Resolution Mass Spectrometry – Although mass spectra usually show the particle masses rounded to the nearest …

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. …

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 …

– 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 …

– In this topic, we will discuss the Characteristic Absorptions of Alcohols and Amines by examples. Characteristic Absorptions of Alcohols and Amines – The O-H bonds of alcohols and the N-H bonds of amines are strong and stiff. – The vibration frequencies of O-H and N-H bonds therefore occur at …

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 …

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 …

First order reaction – Let us consider a first order reaction: A → products – Suppose that at the beginning of the reaction (t = 0), the concentration of A is a moles liter–1. – If after time t, x moles of A have changed, the concentration of A is …

– In this subject, we talk about how to Measure the IR Spectrum. Measurement of the IR Spectrum – Infrared spectra can be measured using liquid, solid, or gaseous samples that are placed in the beam of infrared light. – A drop of a liquid can be placed as a …