Solvent Effects on the Thermodynamic Functions of Dissociation of Anilines and Phenols
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Choosing Buffers Based on Pka in Many Experiments, We Need a Buffer That Maintains the Solution at a Specific Ph. We May Need An
Choosing buffers based on pKa In many experiments, we need a buffer that maintains the solution at a specific pH. We may need an acidic or a basic buffer, depending on the experiment. The Henderson-Hasselbalch equation can help us choose a buffer that has the pH we want. pH = pKa + log([conj. base]/[conj. acid]) With equal amounts of conjugate acid and base (preferred so buffers can resist base and acid equally), then … pH = pKa + log(1) = pKa + 0 = pKa So choose conjugates with a pKa closest to our target pH. Chemistry 103 Spring 2011 Example: You need a buffer with pH of 7.80. Which conjugate acid-base pair should you use, and what is the molar ratio of its components? 2 Chemistry 103 Spring 2011 Practice: Choose the best conjugate acid-base pair for preparing a buffer with pH 5.00. What is the molar ratio of the buffer components? 3 Chemistry 103 Spring 2011 buffer capacity: the amount of strong acid or strong base that can be added to a buffer without changing its pH by more than 1 unit; essentially the number of moles of strong acid or strong base that uses up all of the buffer’s conjugate base or conjugate acid. Example: What is the capacity of the buffer solution prepared with 0.15 mol lactic acid -4 CH3CHOHCOOH (HA, Ka = 1.0 x 10 ) and 0.20 mol sodium lactate NaCH3CHOHCOO (NaA) and enough water to make 1.00 L of solution? (from previous lecture notes) 4 Chemistry 103 Spring 2011 Review of equivalence point equivalence point: moles of H+ = moles of OH- (moles of acid = moles of base, only when the acid has only one acidic proton and the base has only one hydroxide ion). -
Buffers a Guide for the Preparation and Use of Buffers in Biological Systems Calbiochem® Buffers a Guide for the Preparation and Use of Buffers in Biological Systems
Buffers A guide for the preparation and use of buffers in biological systems Calbiochem® Buffers A guide for the preparation and use of buffers in biological systems Chandra Mohan, Ph.D. EMD, San Diego, California © EMD, an affiliate of Merck KGaA, Darmstadt, Germany. All rights reserved. A word to our valued customers We are pleased to present to you the newest edition of Buffers: A Guide for the Preparation and Use of Buffers in Biological Systems. This practical resource has been especially revamped for use by researchers in the biological sciences. This publication is a part of our continuing commitment to provide useful product information and exceptional service to you, our customers. You will find this booklet a highly useful resource, whether you are just beginning your research work or training the newest researchers in your laboratory. Over the past several years, EMD Biosciences has clearly emerged as a world leader in providing highly innovative products for your research needs in Signal Transduction, including the areas of Cancer Biology, Alzheimer’s Disease, Diabetes, Hypertension, Inflammation, and Apoptosis. Please call us today for a free copy of our LATEST Catalog that includes tools for signal transduction and life science research. If you have used our products in the past, we thank you for your support and confidence in our products, and if you are just beginning your research career, please call us and give us the opportunity to demonstrate our exceptional customer and technical service. Corrine Fetherston Sr. Director, Marketing ii Table of Contents: Why does Calbiochem® Biochemicals Publish a Booklet on Buffers? . -
Microscopic Dynamics of Charge Separation at the Aqueous Electrochemical Interface
Microscopic dynamics of charge separation at the aqueous electrochemical interface John A. Kattirtzia,b, David T. Limmerc,d,e,1, and Adam P. Willarda,1 aDepartment of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02138; bCollege of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China; cDepartment of Chemistry, University of California, Berkeley, CA 94609; dKavili Energy NanoScience Institute, University of California, Berkeley, CA 94609; and eMaterial Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94609 Edited by Michael L. Klein, Temple University, Philadelphia, PA, and approved June 6, 2017 (received for review March 7, 2017) We have used molecular simulation and methods of importance the process of aqueous ion association (forward reaction above) sampling to study the thermodynamics and kinetics of ionic or dissociation (reverse reaction above) is deceptively simple. charge separation at a liquid water–metal interface. We have con- The expression omits the cooperative role of solvent, which sidered this process using canonical examples of two different must restructure to accommodate transitions between the asso- classes of ions: a simple alkali–halide pair, Na+I−, or classical ions, ciated and dissociated states (2, 11). This restructuring, which + − and the products of water autoionization, H3O OH , or water is driven by thermal fluctuations, is both collective (extending ions. We find that for both ion classes, the microscopic mecha- beyond the first solvation shell) and fleeting (12–14). These nism of charge separation, including water’s collective role in the microscopic processes are difficult to probe experimentally (15), process, is conserved between the bulk liquid and the electrode so atomistic simulation has played an important role in reveal- interface. -
Superacid Chemistry
SUPERACID CHEMISTRY SECOND EDITION George A. Olah G. K. Surya Prakash Arpad Molnar Jean Sommer SUPERACID CHEMISTRY SUPERACID CHEMISTRY SECOND EDITION George A. Olah G. K. Surya Prakash Arpad Molnar Jean Sommer Copyright # 2009 by John Wiley & Sons, Inc. All rights reserved Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permission. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. -
AMMONIA BUFFER SOLUTION MSDS CAS-No
AMMONIA BUFFER SOLUTION MSDS CAS-No.: MSDS MATERIAL SAFETY DATA SHEET (MSDS) SECTION 1: Identification of the substance/mixture and of the company/undertaking 1.1. Product identifier Product form : Mixture : Product code : 01077 1.2. Relevant identified uses of the substance or mixture and uses advised against 1.2.1. Relevant identified uses Use of the substance/mixture : Laboratory chemicals, Manufacture of substances 1.2.2. Uses advised against No additional information available 1.3. Details of the supplier of the safety data sheet LOBA CHEMIE PVT.LTD. 107 Wode House Road, Jehangir Villa, Colaba 400005 Mumbai - INDIA T +91 22 6663 6663 - F +91 22 6663 6699 [email protected] - www.lobachemie.com 1.4. Emergency telephone number Emergency number : + 91 22 6663 6663 (9:00am - 6:00 pm) SECTION 2: Hazards identification 2.1. Classification of the substance or mixture Classification according to Regulation (EC) No. 1272/2008 [CLP]Mixtures/Substances: SDS EU 2015: According to Regulation (EU) 2015/830 (REACH Annex II) Skin corrosion/irritation, H314 Category 1B Specific target organ H335 toxicity — Single exposure, Category 3, Respiratory tract irritation Hazardous to the aquatic H400 environment — Acute Hazard, Category 1 Full text of hazard classes and H-statements : see section 16 Adverse physicochemical, human health and environmental effects No additional information available www.lobachemie.com 21/04/2016 1/9 AMMONIA BUFFER SOLUTION Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH) with its amendment Regulation (EU) 2015/830 2.2. Label elements Labelling according to Regulation (EC) No. 1272/2008 [CLP] Extra labelling to displayExtra classification(s) to display Hazard pictograms (CLP) : GHS05 GHS07 GHS09 Signal word (CLP) : Danger Hazard statements (CLP) : H314 - Causes severe skin burns and eye damage. -
101 Lime Solvent
Sure Klean® CLEANING & PROTECTIVE TREATMENTS 101 Lime Solvent Sure Klean® 101 Lime Solvent is a concentrated acidic cleaner for dark-colored brick and tile REGULATORY COMPLIANCE surfaces which are not subject to metallic oxidation. VOC Compliance Safely removes excess mortar and construction dirt. Sure Klean® 101 Lime Solvent is compliant with all national, state and district VOC regulations. ADVANTAGES • Removes construction dirt and excess mortar with TYPICAL TECHNICAL DATA simple cold water rinse. Clear, brown liquid • Removes efflorescence from new brick and new FORM Pungent odor stone construction. SPECIFIC GRAVITY 1.12 • Safer than muriatic acid on colored mortar and dark-colored new masonry surfaces. pH 0.50 @ 1:6 dilution • Proven effective since 1954. WT/GAL 9.39 lbs Limitations ACTIVE CONTENT not applicable • Not generally effective in removal of atmospheric TOTAL SOLIDS not applicable stains and black carbon found on older masonry VOC CONTENT not applicable surfaces. Use the appropriate Sure Klean® FLASH POINT not applicable restoration cleaner to remove atmospheric staining from older masonry surfaces. FREEZE POINT <–22° F (<–30° C) • Not for use on polished natural stone. SHELF LIFE 3 years in tightly sealed, • Not for use on treated low-E glass; acrylic and unopened container polycarbonate sheet glazing; and glazing with surface-applied reflective, metallic or other synthetic coatings and films. SAFETY INFORMATION Always read full label and SDS for precautionary instructions before use. Use appropriate safety equipment and job site controls during application and handling. 24-Hour Emergency Information: INFOTRAC at 800-535-5053 Product Data Sheet • Page 1 of 4 • Item #10010 – 102715 • ©2015 PROSOCO, Inc. -
Title a Hydronium Solvate Ionic Liquid
A Hydronium Solvate Ionic Liquid: Facile Synthesis of Air- Title Stable Ionic Liquid with Strong Bronsted Acidity Kitada, Atsushi; Takeoka, Shun; Kintsu, Kohei; Fukami, Author(s) Kazuhiro; Saimura, Masayuki; Nagata, Takashi; Katahira, Masato; Murase, Kuniaki Journal of the Electrochemical Society (2018), 165(3): H121- Citation H127 Issue Date 2018-02-22 URL http://hdl.handle.net/2433/240665 © The Author(s) 2018. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, Right http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. Type Journal Article Textversion publisher Kyoto University Journal of The Electrochemical Society, 165 (3) H121-H127 (2018) H121 A Hydronium Solvate Ionic Liquid: Facile Synthesis of Air-Stable Ionic Liquid with Strong Brønsted Acidity Atsushi Kitada, 1,z Shun Takeoka,1 Kohei Kintsu,1 Kazuhiro Fukami,1,∗ Masayuki Saimura,2 Takashi Nagata,2 Masato Katahira,2 and Kuniaki Murase1,∗ 1Department of Materials Science and Engineering, Kyoto University, Yoshida-honmachi, Sakyo, Kyoto 606-8501, Japan 2Institute of Advanced Energy, Gokasho, Uji, Kyoto 611-0011, Japan + A new kind of ionic liquid (IL) with strong Brønsted acidity, i.e., a hydronium (H3O ) solvate ionic liquid, is reported. The IL can + + be described as [H3O · 18C6]Tf2N, where water exists as the H3O ion solvated by 18-crown-6-ether (18C6), of which the counter – – + anion is bis(trifluoromethylsulfonyl)amide (Tf2N ;Tf= CF3SO2). The hydrophobic Tf2N anion makes [H3O · 18C6]Tf2N stable + in air. -
Hydrated Sulfate Clusters SO4^2
Article Cite This: J. Phys. Chem. B 2019, 123, 4065−4069 pubs.acs.org/JPCB 2− n − Hydrated Sulfate Clusters SO4 (H2O)n ( =1 40): Charge Distribution Through Solvation Shells and Stabilization Maksim Kulichenko,† Nikita Fedik,† Konstantin V. Bozhenko,‡,§ and Alexander I. Boldyrev*,† † Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300, United States ‡ Department of Physical and Colloid Chemistry, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russian Federation § Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432, Moscow Region, Russian Federation *S Supporting Information 2− ABSTRACT: Investigations of inorganic anion SO4 interactions with water are crucial 2− for understanding the chemistry of its aqueous solutions. It is known that the isolated SO4 dianion is unstable, and three H2O molecules are required for its stabilization. In the 2− current work, we report our computational study of hydrated sulfate clusters SO4 (H2O)n (n =1−40) in order to understand the nature of stabilization of this important anion by fi 2− water molecules. We showed that the most signi cant charge transfer from dianion SO4 ≤ 2− to H2O takes place at a number of H2O molecules n 7. The SO4 directly donates its charge only to the first solvation shell and surprisingly, a small amount of electron density of 0.15|e| is enough to be transferred in order to stabilize the dianion. Upon further addition of ff ≤ H2O molecules, we found that the cage e ect played an essential role at n 12, where the fi 2− | | rst solvation shell closes. -
Solvation Structure of Ions in Water
International Journal of Thermophysics, Vol. 28, No. 2, April 2007 (© 2007) DOI: 10.1007/s10765-007-0154-6 Solvation Structure of Ions in Water Raymond D. Mountain1 Molecular dynamics simulations of ions in water are reported for solutions of varying solute concentration at ambient conditions for six cations and four anions in 10 solutes. The solutes were selected to show trends in properties as the size and charge density of the ions change. The emphasis is on how the structure of water is modified by the presence of the ions and how many water molecules are present in the first solvation shell of the ions. KEY WORDS: anion; cation; molecular dynamics; potential functions; solva- tion; water. 1. INTRODUCTION The behavior of aqueous solutions of salts is a topic of continuing interest [1–3]. In this note we examine how the structure of water,as reflected in the oxy- gen–oxygen pair function, is modified as the concentration of ions increases. The method of generating the pair functions is molecular dynamics using the SPC/E model for water [4] and various models for ion–water interactions taken from the literature. The solutes are LiCl, NaCl, KCl, RbCl, NaF, CaCl2, CaSO4,Na2SO4, NaNO3, and guanidinium chloride (GdmCl) [C(NH2)3Cl]. This work is an extension of earlier work [5] to a larger set of ions. The water molecules and ions interact through site–site pair interac- tions consisting of Lennard–Jones potentials and Coulomb interactions so that the interaction between a pair of sites labeled i, j and separated by an interatomic distance r is 12 6 φij (r) = 4ij (σij /r) − (σij /r) + qiqj /r (1) where qi is the charge on site i. -
Solvent-Tunable Binding of Hydrophilic and Hydrophobic Guests by Amphiphilic Molecular Baskets Yan Zhao Iowa State University, [email protected]
Chemistry Publications Chemistry 8-2005 Solvent-Tunable Binding of Hydrophilic and Hydrophobic Guests by Amphiphilic Molecular Baskets Yan Zhao Iowa State University, [email protected] Eui-Hyun Ryu Iowa State University Follow this and additional works at: http://lib.dr.iastate.edu/chem_pubs Part of the Chemistry Commons The ompc lete bibliographic information for this item can be found at http://lib.dr.iastate.edu/ chem_pubs/197. For information on how to cite this item, please visit http://lib.dr.iastate.edu/ howtocite.html. This Article is brought to you for free and open access by the Chemistry at Iowa State University Digital Repository. It has been accepted for inclusion in Chemistry Publications by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Solvent-Tunable Binding of Hydrophilic and Hydrophobic Guests by Amphiphilic Molecular Baskets Abstract Responsive amphiphilic molecular baskets were obtained by attaching four facially amphiphilic cholate groups to a tetraaminocalixarene scaffold. Their binding properties can be switched by solvent changes. In nonpolar solvents, the molecules utilize the hydrophilic faces of the cholates to bind hydrophilic molecules such as glucose derivatives. In polar solvents, the molecules employ the hydrophobic faces of the cholates to bind hydrophobic guests. A water-soluble basket can bind polycyclic aromatic hydrocarbons including anthracene, pyrene, and perylene. The binding free energy (−ΔG) ranges from 5 to 8 kcal/mol and is directly proportional to the surface area of the aromatic hosts. Binding of both hydrophilic and hydrophobic guests is driven by solvophobic interactions. Disciplines Chemistry Comments Reprinted (adapted) with permission from Journal of Organic Chemistry 70 (2005): 7585, doi:10.1021/ jo051127f. -
I. the Nature of Solutions
Solutions The Nature of Solutions Definitions Solution - homogeneous mixture Solute - substance being dissolved Solvent - present in greater amount Types of Solutions SOLUTE – the part of a Solute Solvent Example solution that is being dissolved (usually the solid solid ? lesser amount) solid liquid ? SOLVENT – the part of a solution that gas solid ? dissolves the solute (usually the greater liquid liquid ? amount) gas liquid ? Solute + Solvent = Solution gas gas ? Is it a Solution? Homogeneous Mixture (Solution) Tyndall no Effect? Solution Is it a Solution? Solution • homogeneous • very small particles • no Tyndall effect • particles don’t settle • Ex: •rubbing alcohol Is it a Solution? Homogeneous Mixture (Solution) Tyndall no Effect? yes Solution Suspension, Colloid, or Emulsion Will mixture separate if allowed to stand? no Colloid (very fine solid in liquid) Is it a Solution? Colloid • homogeneous • very fine particles • Tyndall effect • particles don’t settle • Ex: •milk Is it a Solution? Homogeneous Mixture (Solution) Tyndall Effect? no yes Solution Suspension, Colloid, or Emulsion Will mixture separate if allowed to stand? no yes Colloid Suspension or Emulsion Solid or liquid particles? solid Suspension (course solid in liquid) Is it a Solution? Suspension • homogeneous • large particles • Tyndall effect • particles settle if given enough time • Ex: • Pepto-Bismol • Fresh-squeezed lemonade Is it a Solution? Homogeneous Mixture (Solution) Tyndall no Effect? yes Solution Suspension, Colloid, or Emulsion Will mixture separate if allowed to stand? no yes Colloid Suspension or Emulsion Solid or liquid particles? solid liquid Suspension (course solid in liquid) Emulsion (liquid in liquid) Is it a Solution? Emulsion • homogeneous • mixture of two immiscible liquids • Tyndall effect • particles settle if given enough time • Ex: • Mayonnaise Pure Substances vs. -
Affinity of Small-Molecule Solutes to Hydrophobic, Hydrophilic, and Chemically Patterned Interfaces in Aqueous Solution
Affinity of small-molecule solutes to hydrophobic, hydrophilic, and chemically patterned interfaces in aqueous solution Jacob I. Monroea, Sally Jiaoa, R. Justin Davisb, Dennis Robinson Browna, Lynn E. Katzb, and M. Scott Shella,1 aDepartment of Chemical Engineering, University of California, Santa Barbara, CA 93106; and bDepartment of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78712 Edited by Peter J. Rossky, Rice University, Houston, TX, and approved November 17, 2020 (received for review September 30, 2020) Performance of membranes for water purification is highly influ- However, a molecular understanding that links membrane enced by the interactions of solvated species with membrane surface chemistry to solute affinity and hence membrane func- surfaces, including surface adsorption of solutes upon fouling. tional properties remains incomplete, due in part to the complex Current efforts toward fouling-resistant membranes often pursue interplay among specific interactions (e.g., hydrogen bonds, surface hydrophilization, frequently motivated by macroscopic electrostatics, dispersion) and molecular morphology (e.g., sur- measures of hydrophilicity, because hydrophobicity is thought to face and polymer configurations) that are difficult to disentangle increase solute–surface affinity. While this heuristic has driven di- (11–14). Chemically heterogeneous surfaces are even less un- verse membrane functionalization strategies, here we build on derstood but can affect fouling in complex ways.