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– In the this topic we talk about Stereochemical Nonequivalence of Protons in NMR Spectroscopy. Stereochemical Nonequivalence of Protons – Stereochemical differences often result in different chemical shifts for protons on the same carbon atom. – For example, the two protons on C1 of allyl bromide (3-bromopropene) are not equivalent. …

– In this subject, we will discuss the Associated Colloids. Associated Colloids – The molecules of substances as soaps and artificial detergents are smaller than the colloidal particles. However in concentrated solutions these molecules form aggregates of colloidal size. – Substances whose molecules aggregate spontaneously in a given solvent to …

Electrical Properties of Sols – In this topic we will discuss the Electrical Properties of Sols as follow: (1) The sol particles carry an electric charge. (2) Electrophoresis. (3) Electro-osmosis. (4) Coagulation or Precipitation. (5) Protective action of sols. (6) Origin of charge on sol particles. (1) The sol particles …

– In this subject, we will discuss the Reagents for Neutralization Titrations. Reagents for Neutralization Titrations – we noted before that strong acids and strong bases produce the largest change in pH at the equivalence point. – For this reason, standard solutions for neutralization titrations are always prepared from these …

Kinetic Properties of Sols – In this topic, we will discuss Kinetic Properties of Sols. Brownian Movement – When a sol is examined with an ultramicroscope, the suspended particles are seen as shining specks of light. – By following an individual particle it is observed that the particle is undergoing …

Optical Properties of Sols – In this topic, we will discuss Optical Properties of Sols as follow: Sols exhibit Tyndall effect Ultramicroscope shows up the presence of individual particles Sol particles can be seen with an Electron microscope (1) Sols exhibit Tyndall effect – When a strong beam of light …

– In the last topic we talk about Spin-Spin Splitting in ¹H NMR Spectra, but In this topic, we will discuss The Complex Splitting. Complex Splitting in ¹H NMR Spectra – There are many cases of complex splitting, where signals are split by adjacent protons of more than one type, …

– In this topic, we will discuss The Composition of Solutions During acid/Base Titration. The Composition of Solutions During acid/Base Titration – We are often interested in the changes in composition that occur while a solution of a weak acid or a weak base is being titrated. – These changes …

– In this topic, we will discuss The titration Curves for Weak Bases. Titration Curves for Weak Bases – The calculations needed to draw the titration curves for weak bases are analogous to those of a weak acid, as shown in The following Example . A 50.00-mL aliquot of 0.0500 …

– In this topic, we will discuss Preparation of Sols, Purification of Sols and its colors Preparation of Sols – Lyophilic sols may be prepared by simply warming the solid with the liquid dispersion medium e.g., starch with water. – On the other hand, lyophobic sols have to be prepared …

Titration Curves for Weak Acids – Four distinctly different types of calculations are needed to compute values for a weak acid (or a weak base) titration curves: (1) At the beginning, the solution contains only a weak acid or a weak base, and the pH is calculated from the concentration …

– In this topic, we will discuss The Spin-Spin Splitting in ¹H NMR Spectra. Theory of Spin-Spin Splitting – A proton in the NMR spectrometer is subjected to both the external magnetic field and the induced field of the shielding electrons. – If there are other protons nearby, their small …

– In this topic, we will discuss The Lyophilic and Lyophobic sols : Defination, Characteristics, and Comparison. Defination of Lyophilic and Lyophobic sols – Sols are colloidal systems in which a solid is dispersed in a liquid. – These can be subdivided into two classes : Lyophilic sols (solvent-loving) Lyophobic …

– In this topic, we will discuss The Titration of Strong Acids and Bases. Introduction to Titration of Strong Acids and Bases – The hydronium ions in an aqueous solution of a strong acid have two sources: (1) the reaction of the acid with water. (2) the dissociation of water …

– In this topic, we will discuss the Indicators and Solutions for acid-base titration. Indicators and Solutions for acid-base titration – Like all titrations, neutralization titrations depend on a chemical reaction of the analyte with a standard reagent. – There are several different types of acid/base titrations. – One of …

– In this topic, we will discuss the Titration Curves in Analytical Chemistry : Definition and Types Titration Curves – An end point is signaled by an observable physical change near the equivalence point of a titration. – The two most widely used signals involve (1) changes in color due …

Gravimetric titrations – Mass (weight) or gravimetric titrations differ from their volumetric counterparts in that the mass of titrant is measured rather than the volume. – Therefore, in a mass titration, a balance and a weighable solution dispenser are substituted for a buret and its markings. – Gravimetric titrations actually …

– In this topic, we will discuss The Areas of the Peaks in NMR Spectroscopy Areas of the Peaks – The area under a peak is proportional to the number of hydrogens contributing to that peak. – For example, in the methyl tert-butyl ether spectrum (Figure 1), the absorption of …

The Number of Signals – In general, the number of NMR signals corresponds to the number of different kinds of protons present in the molecule. – For example, methyl tert-butyl ether has two types of protons (Figure 1). – The three methoxy protons are chemically identical, and they give rise …

– In this topic, we will discuss the colloids: definition, History and Types History of colloids – Thomas Graham (1861) studied the ability of dissolved substances to diffuse into water across a permeable membrane. – He observed that crystalline substances such as sugar, urea, and sodium chloride passed through the …