Solutions and Colloids 603
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Photocatalytic Performance of Cuxo/Tio2 Deposited by Hipims on Polyester Under Visible Light Leds: Oxidants, Ions Effect, and Reactive Oxygen Species Investigation
materials Article Photocatalytic Performance of CuxO/TiO2 Deposited by HiPIMS on Polyester under Visible Light LEDs: Oxidants, Ions Effect, and Reactive Oxygen Species Investigation Hichem Zeghioud 1 , Aymen Amine Assadi 2,*, Nabila Khellaf 3, Hayet Djelal 4, Abdeltif Amrane 2 and Sami Rtimi 5,* 1 Department of Process Engineering, Faculty of Engineering, Badji Mokhtar University, P.O. Box 12, 23000 Annaba, Algeria; [email protected] 2 Ecole Nationale Supérieure de Chimie de Rennes, Université de Rennes 1, CNRS, UMR 6226, Allée de Beaulieu, CS 50837, 35708 Rennes CEDEX 7, France; [email protected] 3 Laboratory of Organic Synthesis-Modeling and Optimization of Chemical Processes, Badji Mokhtar University, P.O. Box 12, 23000 Annaba, Algeria; [email protected] 4 Ecole des Métiers de l’Environnement, Campus de Ker Lann, 35170 Bruz, France; [email protected] 5 Ecole Polytechnique Fédérale de Lausanne, EPFL-STI-LTP, Station 12, CH-1015 Lausanne, Switzerland * Correspondence: [email protected] (A.A.A.); sami.rtimi@epfl.ch (S.R.) Received: 29 December 2018; Accepted: 22 January 2019; Published: 29 January 2019 Abstract: In the present study, we propose a new photocatalytic interface prepared by high-power impulse magnetron sputtering (HiPIMS), and investigated for the degradation of Reactive Green 12 (RG12) as target contaminant under visible light light-emitting diodes (LEDs) illumination. The CuxO/TiO2 nanoparticulate photocatalyst was sequentially sputtered on polyester (PES). The photocatalyst formulation was optimized by investigating the effect of different parameters such as the sputtering time of CuxO, the applied current, and the deposition mode (direct current magnetron sputtering, DCMS or HiPIMS). -
Working with Hazardous Chemicals
A Publication of Reliable Methods for the Preparation of Organic Compounds Working with Hazardous Chemicals The procedures in Organic Syntheses are intended for use only by persons with proper training in experimental organic chemistry. All hazardous materials should be handled using the standard procedures for work with chemicals described in references such as "Prudent Practices in the Laboratory" (The National Academies Press, Washington, D.C., 2011; the full text can be accessed free of charge at http://www.nap.edu/catalog.php?record_id=12654). All chemical waste should be disposed of in accordance with local regulations. For general guidelines for the management of chemical waste, see Chapter 8 of Prudent Practices. In some articles in Organic Syntheses, chemical-specific hazards are highlighted in red “Caution Notes” within a procedure. It is important to recognize that the absence of a caution note does not imply that no significant hazards are associated with the chemicals involved in that procedure. Prior to performing a reaction, a thorough risk assessment should be carried out that includes a review of the potential hazards associated with each chemical and experimental operation on the scale that is planned for the procedure. Guidelines for carrying out a risk assessment and for analyzing the hazards associated with chemicals can be found in Chapter 4 of Prudent Practices. The procedures described in Organic Syntheses are provided as published and are conducted at one's own risk. Organic Syntheses, Inc., its Editors, and its Board of Directors do not warrant or guarantee the safety of individuals using these procedures and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures herein. -
Solutes and Solution
Solutes and Solution The first rule of solubility is “likes dissolve likes” Polar or ionic substances are soluble in polar solvents Non-polar substances are soluble in non- polar solvents Solutes and Solution There must be a reason why a substance is soluble in a solvent: either the solution process lowers the overall enthalpy of the system (Hrxn < 0) Or the solution process increases the overall entropy of the system (Srxn > 0) Entropy is a measure of the amount of disorder in a system—entropy must increase for any spontaneous change 1 Solutes and Solution The forces that drive the dissolution of a solute usually involve both enthalpy and entropy terms Hsoln < 0 for most species The creation of a solution takes a more ordered system (solid phase or pure liquid phase) and makes more disordered system (solute molecules are more randomly distributed throughout the solution) Saturation and Equilibrium If we have enough solute available, a solution can become saturated—the point when no more solute may be accepted into the solvent Saturation indicates an equilibrium between the pure solute and solvent and the solution solute + solvent solution KC 2 Saturation and Equilibrium solute + solvent solution KC The magnitude of KC indicates how soluble a solute is in that particular solvent If KC is large, the solute is very soluble If KC is small, the solute is only slightly soluble Saturation and Equilibrium Examples: + - NaCl(s) + H2O(l) Na (aq) + Cl (aq) KC = 37.3 A saturated solution of NaCl has a [Na+] = 6.11 M and [Cl-] = -
An Analysis of Electrophilic Aromatic Substitution: a “Complex Approach” PCCP
Volume 23 Number 9 7 March 2021 Pages 5033–5682 PCCP Physical Chemistry Chemical Physics rsc.li/pccp ISSN 1463-9076 PERSPECTIVE Janez Cerkovnik et al . An analysis of electrophilic aromatic substitution: a “complex approach” PCCP View Article Online PERSPECTIVE View Journal | View Issue An analysis of electrophilic aromatic substitution: a ‘‘complex approach’’† Cite this: Phys. Chem. Chem. Phys., a a b 2021, 23, 5051 Nikola Stamenkovic´, Natasˇa Poklar Ulrih and Janez Cerkovnik * Electrophilic aromatic substitution (EAS) is one of the most widely researched transforms in synthetic organic chemistry. Numerous studies have been carried out to provide an understanding of the nature of its reactivity pattern. There is now a need for a concise and general, but detailed and up-to-date, overview. The basic principles behind EAS are essential to our understanding of what the mechanisms underlying EAS are. To date, textbook overviews of EAS have provided little information about the Received 5th October 2020, mechanistic pathways and chemical species involved. In this review, the aim is to gather and present the Accepted 21st December 2020 up-to-date information relating to reactivity in EAS, with the implication that some of the key concepts DOI: 10.1039/d0cp05245k will be discussed in a scientifically concise manner. In addition, the information presented herein suggests certain new possibilities to advance EAS theory, with particular emphasis on the role of modern Creative Commons Attribution-NonCommercial 3.0 Unported Licence. rsc.li/pccp -
Equation of State for Benzene for Temperatures from the Melting Line up to 725 K with Pressures up to 500 Mpa†
High Temperatures-High Pressures, Vol. 41, pp. 81–97 ©2012 Old City Publishing, Inc. Reprints available directly from the publisher Published by license under the OCP Science imprint, Photocopying permitted by license only a member of the Old City Publishing Group Equation of state for benzene for temperatures from the melting line up to 725 K with pressures up to 500 MPa† MONIKA THOL ,1,2,* ERIC W. Lemm ON 2 AND ROLAND SPAN 1 1Thermodynamics, Ruhr-University Bochum, Universitaetsstrasse 150, 44801 Bochum, Germany 2National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA Received: December 23, 2010. Accepted: April 17, 2011. An equation of state (EOS) is presented for the thermodynamic properties of benzene that is valid from the triple point temperature (278.674 K) to 725 K with pressures up to 500 MPa. The equation is expressed in terms of the Helmholtz energy as a function of temperature and density. This for- mulation can be used for the calculation of all thermodynamic properties. Comparisons to experimental data are given to establish the accuracy of the EOS. The approximate uncertainties (k = 2) of properties calculated with the new equation are 0.1% below T = 350 K and 0.2% above T = 350 K for vapor pressure and liquid density, 1% for saturated vapor density, 0.1% for density up to T = 350 K and p = 100 MPa, 0.1 – 0.5% in density above T = 350 K, 1% for the isobaric and saturated heat capaci- ties, and 0.5% in speed of sound. Deviations in the critical region are higher for all properties except vapor pressure. -
Determination of the Identity of an Unknown Liquid Group # My Name the Date My Period Partner #1 Name Partner #2 Name
Determination of the Identity of an unknown liquid Group # My Name The date My period Partner #1 name Partner #2 name Purpose: The purpose of this lab is to determine the identity of an unknown liquid by measuring its density, melting point, boiling point, and solubility in both water and alcohol, and then comparing the results to the values for known substances. Procedure: 1) Density determination Obtain a 10mL sample of the unknown liquid using a graduated cylinder Determine the mass of the 10mL sample Save the sample for further use 2) Melting point determination Set up an ice bath using a 600mL beaker Obtain a ~5mL sample of the unknown liquid in a clean dry test tube Place a thermometer in the test tube with the sample Place the test tube in the ice water bath Watch for signs of crystallization, noting the temperature of the sample when it occurs Save the sample for further use 3) Boiling point determination Set up a hot water bath using a 250mL beaker Begin heating the water in the beaker Obtain a ~10mL sample of the unknown in a clean, dry test tube Add a boiling stone to the test tube with the unknown Open the computer interface software, using a graph and digit display Place the temperature sensor in the test tube so it is in the unknown liquid Record the temperature of the sample in the test tube using the computer interface Watch for signs of boiling, noting the temperature of the unknown Dispose of the sample in the assigned waste container 4) Solubility determination Obtain two small (~1mL) samples of the unknown in two small test tubes Add an equal amount of deionized into one of the samples Add an equal amount of ethanol into the other Mix both samples thoroughly Compare the samples for solubility Dispose of the samples in the assigned waste container Observations: The unknown is a clear, colorless liquid. -
Parametrisation in Electrostatic DPD Dynamics and Applications
Parametrisation in electrostatic DPD Dynamics and Applications E. Mayoraly and E. Nahmad-Acharz February 19, 2016 y Instituto Nacional de Investigaciones Nucleares, Carretera M´exico-Toluca S/N, La Marquesa Ocoyoacac, Edo. de M´exicoC.P. 52750, M´exico z Instituto de Ciencias Nucleares, Universidad Nacional Aut´onomade M´exico, Apartado Postal 70-543, 04510 M´exico DF, Mexico abstract A brief overview of mesoscopic modelling via dissipative particle dynamics is presented, with emphasis on the appropriate parametrisation and how to cal- culate the relevant parameters for given realistic systems. The dependence on concentration and temperature of the interaction parameters is also considered, as well as some applications. 1 Introduction In a colloidal dispersion, the stability is governed by the balance between Van der Waals attractive forces and electrostatic repulsive forces, together with steric mechanisms. Being able to model their interplay is of utmost importance to predict the conditions for colloidal stability, which in turn is of major interest in basic research and for industrial applications. Complex fluids are composed typically at least of one or more solvents, poly- meric or non-polymeric surfactants, and crystalline substrates onto which these surfactants adsorb. Neutral polymer adsorption has been extensively studied us- ing mean-field approximations and assuming an adsorbed polymer configuration of loops and tails [1,2,3,4]. Different mechanisms of adsorption affecting the arXiv:1602.05935v1 [physics.chem-ph] 18 Feb 2016 global -
1.1 10 Oxidation of Alcohols and Aldehydes
1.1 10 Oxidation of alcohols and aldehydes By the end of this spread, you should be able to … 1Describe the oxidation of primary alcohols to form aldehydes and carboxylic acids. 1Describe the oxidation of secondary alcohols to form ketones. 1Describe the oxidation of aldehydes to form carboxylic acids. Key definition Oxidation of alcohols You will recall from your AS chemistry studies that primary and secondary alcohols can A redox reaction is one in which both reduction and oxidation take place. be oxidised using an oxidising agent. s !SUITABLEOXIDISINGAGENTISASOLUTIONCONTAININGACIDIlEDDICHROMATEIONS + 2− H /Cr2O7 . s 4HEOXIDISINGMIXTURECANBEMADEFROMPOTASSIUMDICHROMATE +2Cr2O7, and sulfuric acid, H2SO. During the reaction, the acidified potassium dichromate changes from orange to green. Remember that tertiary alcohols are not oxidised by acidified dichromate ions. Primary alcohols Primary alcohols can be oxidised to aldehydes and to carboxylic acids (see AS Chemistry spread 2.2.3). H H H O H O Oxidation Oxidation H CCOH H CC H CC H H H H H OH Primary alcohol Aldehyde Carboxylic acid Figure 1 Ethanol oxidised to ethanal, and finally to ethanoic acid The equation for the oxidation of ethanol to the aldehyde ethanal is shown below. Note that the oxidising agent is shown as [O] – this simplifies the equation. CH3CH2OH + [O] }m CH3CHO + H2O When preparing aldehydes in the laboratory, you will need to distil the aldehyde from the reaction mixture as it is formed. This prevents the aldehyde from being oxidised further to a carboxylic acid. Key definition When making the carboxylic acid, the reaction mixture is usually heated under reflux before distilling the product off. -
Molarity Versus Molality Concentration of Solutions SCIENTIFIC
Molarity versus Molality Concentration of Solutions SCIENTIFIC Introduction Simple visual models using rubber stoppers and water in a cylinder help to distinguish between molar and molal concentrations of a solute. Concepts • Solutions • Concentration Materials Graduated cylinder, 1-L, 2 Water, 2-L Rubber stoppers, large, 12 Safety Precautions Watch for spills. Wear chemical splash goggles and always follow safe laboratory procedures when performing demonstrations. Procedure 1. Tell the students that the rubber stoppers represent “moles” of solute. 2. Make a “6 Molar” solution by placing six of the stoppers in a 1-L graduated cylinder and adding just enough water to bring the total volume to 1 liter. 3. Now make a “6 molal” solution by adding six stoppers to a liter of water in the other cylinder. 4. Remind students that a kilogram of water is about equal to a liter of water because the density is about 1 g/mL at room temperature. 5. Set the two cylinders side by side for comparison. Disposal The water may be flushed down the drain. Discussion Molarity, moles of solute per liter of solution, and molality, moles of solute per kilogram of solvent, are concentration expressions that students often confuse. The differences may be slight with dilute aqueous solutions. Consider, for example, a dilute solution of sodium hydroxide. A 0.1 Molar solution consists of 4 g of sodium hydroxide dissolved in approximately 998 g of water, while a 0.1 molal solution consists of 4 g of sodium hydroxide dissolved in 1000 g of water. The amount of water in both solutions is virtually the same. -
The Basics of Vapor-Liquid Equilibrium (Or Why the Tripoli L2 Tech Question #30 Is Wrong)
The Basics of Vapor-Liquid Equilibrium (Or why the Tripoli L2 tech question #30 is wrong) A question on the Tripoli L2 exam has the wrong answer? Yes, it does. What is this errant question? 30.Above what temperature does pressurized nitrous oxide change to a gas? a. 97°F b. 75°F c. 37°F The correct answer is: d. all of the above. The answer that is considered correct, however, is: a. 97ºF. This is the critical temperature above which N2O is neither a gas nor a liquid; it is a supercritical fluid. To understand what this means and why the correct answer is “all of the above” you have to know a little about the behavior of liquids and gases. Most people know that water boils at 212ºF. Most people also know that when you’re, for instance, boiling an egg in the mountains, you have to boil it longer to fully cook it. The reason for this has to do with the vapor pressure of water. Every liquid wants to vaporize to some extent. The measure of this tendency is known as the vapor pressure and varies as a function of temperature. When the vapor pressure of a liquid reaches the pressure above it, it boils. Until then, it evaporates until the fraction of vapor in the mixture above it is equal to the ratio of the vapor pressure to the total pressure. At that point it is said to be in equilibrium and no further liquid will evaporate. The vapor pressure of water at 212ºF is 14.696 psi – the atmospheric pressure at sea level. -
Liquid-Vapor Equilibrium in a Binary System
Liquid-Vapor Equilibria in Binary Systems1 Purpose The purpose of this experiment is to study a binary liquid-vapor equilibrium of chloroform and acetone. Measurements of liquid and vapor compositions will be made by refractometry. The data will be treated according to equilibrium thermodynamic considerations, which are developed in the theory section. Theory Consider a liquid-gas equilibrium involving more than one species. By definition, an ideal solution is one in which the vapor pressure of a particular component is proportional to the mole fraction of that component in the liquid phase over the entire range of mole fractions. Note that no distinction is made between solute and solvent. The proportionality constant is the vapor pressure of the pure material. Empirically it has been found that in very dilute solutions the vapor pressure of solvent (major component) is proportional to the mole fraction X of the solvent. The proportionality constant is the vapor pressure, po, of the pure solvent. This rule is called Raoult's law: o (1) psolvent = p solvent Xsolvent for Xsolvent = 1 For a truly ideal solution, this law should apply over the entire range of compositions. However, as Xsolvent decreases, a point will generally be reached where the vapor pressure no longer follows the ideal relationship. Similarly, if we consider the solute in an ideal solution, then Eq.(1) should be valid. Experimentally, it is generally found that for dilute real solutions the following relationship is obeyed: psolute=K Xsolute for Xsolute<< 1 (2) where K is a constant but not equal to the vapor pressure of pure solute. -
Nucleophilic Aromatic Substitution on Aryl-Amido Ligands Promoted by Oxidizing Osmium(IV) Centers
Inorg. Chem. 2004, 43, 5804−5815 Nucleophilic Aromatic Substitution on Aryl-Amido Ligands Promoted by Oxidizing Osmium(IV) Centers Jake D. Soper, Erik Saganic, David Weinberg, David A. Hrovat, Jason B. Benedict,† Werner Kaminsky,† and James M. Mayer* Department of Chemistry, Campus Box 351700, UniVersity of Washington, Seattle, Washington 98195-1700 Received January 30, 2004 IV Addition of amine nucleophiles to acetonitrile solutions of the Os anilido complex TpOs(NHPh)Cl2 (1) [Tp ) hydrotris(1-pyrazolyl)borate] gives products with derivatized anilido ligands, i.e., TpOs[NH-p-C6H4(N(CH2)5)]Cl2 (2) from piperidine and TpOs[NH-p-C6H4N(CH2)4]Cl2 (3) from pyrrolidine. These materials are formed in ∼30% yield III under anaerobic conditions, together with ∼60% yields of the Os aniline complex TpOs(NH2Ph)Cl2 (5). Formation of the para-substituted materials 2 or 3 from 1 involves oxidative removal of two hydrogen atoms (two H+ and two - e ). The oxidation can be accomplished by 1, forming 5,orbyO2. Related reactions have been observed with other amines and with the 2-naphthylamido derivative, which gives an ortho-substituted product. Kinetic studies indicate an addition−elimination mechanism involving initial attack of the amine nucleophile on the anilido ligand. These are unusual examples of nucleophilic aromatic substitution of hydrogen. Ab initio calculations on 1 show that the LUMO has significant density at the ortho and para positions of the anilido ligand, resembling the LUMO of nitrobenzene. By analogy with nucleophilic aromatic substitution, 2 is quantitatively formed from piperidine and IV the p-chloroanilide TpOs(NH-p-C6H4Cl)Cl2 (7).