Some New Compounds of Urea with Acids and Salts
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Department of Chemistry
ST.PHILOMENA’S COLLEGE (AUTONOMOUS), MYSURU (AFFILIATED TO UNIVERSITY OF MYSORE) REACCREDITED BY NAAC WITH A GRADE COURSE – B.Sc Three-year six semesters Choice Based Credit System (CBCS) and Continuous Assessment & Grading Pattern (CAGP) Under Graduate Programme under Autonomous Structure Academic year 2018-19 onwards DEPARTMENT OF CHEMISTRY St. Philomena’s College (Autonomous) Mysuru. B.Sc., Chemistry Syllabus - CBCS Scheme 2018-19 onwards. Page 1 PREAMBLE For the development of any Society, Science education plays an important role. Chemistry, being a major component of Science, is one of the increasingly important disciplinary areas of Science. Chemistry, which is also studied at the Bachelor’s degree programme for years, has been witnessing a slow transition from an analog to a much- needed one. It is an experimental science and students need to be trained both in the theoretical & practical aspects to get expertise. Moreover, the topics prescribed should provide in-depth knowledge of the subject and also the relevant basic allied subjects. Under this context, in order to make the U. G. teaching more effective and meaningful, revamping the syllabus is the need of the hour. It is certain that systematic and planned curricula from first to the third year shall motivate and encourage students for pursuing higher studies in various disciplines of chemistry such as Inorganic, organic, Physical, Analytical and Bio-Chemistry. This curriculum also enables the students to shoulder the responsibility as chemists in chemical industry. Thus, an updated and content revision of UG Chemistry syllabus is essential to improve its quality at the National and International level and also to meet the present-day challenges of PG and research oriented work after the PG programme. -
2-‐Bromobutane
Practice Questions 1. What is true about the reaction between (R)-2-bromobutane and potassium cyanide as shown below? Br KCN a) The product is a racemic mixture. b) The product is (S)-2-cyanobutane. c) The mechanism proceeds through a stable intermediate. d) The mechanism proceeds through a single transition state step. e) Answers a and c. f) Answers b and d. 2. The following reaction goes through an SN2 mechanism. - - CH3CH2CH2Br + OH à CH3CH2CH2OH + Br At constant temperature, what is the effect on the rate of the reaction by simultaneously doubling the concentration of propyl bromide and OH- ion? a) It would increase the rate by six. b) It would double the rate. c) It would triple the rate. d) It would increase the rate by four. e) It would have no effect on the rate. 3. Which is the minor substitution product in the following reaction? a) I b) II c) III d) Equal amounts of I and II e) None of these products 4. What is the major product of the following reaction? a) I b) II c) III d) IV e) Equal amount of I and III 5. Consider the reaction between 2-bromo-2,4-dimethylpentane and sodium iodide, NaI, in acetone. Br NaI I acetone At constant temperature, what is the effect on the reaction rate if one simultaneously double the concentration of 2-bromo-2,4-dimethylpentane and sodium iodide? a) It would double the reaction rate. b) It would triple the reaction rate. c) It would quadruple the reaction rate. d) It would increase the reaction rate by 5. -
Ammonia Snow-Lines and Ammonium Salts Desorption ? F
Astronomy & Astrophysics manuscript no. aanda_ammonium-salts ©ESO 2021 April 22, 2021 Ammonia snow-lines and ammonium salts desorption ? F. Kruczkiewicz1; 2; 3, J. Vitorino2, E. Congiu2, P. Theulé1, and F. Dulieu2 1 Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France e-mail: [email protected] 2 CY Cergy Paris Université, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, LERMA, F-95000, Cergy, France 3 Max-Planck-Institut für extraterrestrische Physik, Gießenbachstraße 1, Garching, 85748, Germany Received –; accepted – ABSTRACT Context. The nitrogen reservoir in planetary systems is a long standing problem. Part of the N-bearing molecules is probably incor- porated into the ice bulk during the cold phases of the stellar evolution, and may be gradually released into the gas phase when the ice is heated, such as in active comets. The chemical nature of the N-reservoir should greatly influence how, when and in what form N returns to the gas phase, or is incorporated into the refractory material forming planetary bodies. Aims. We present the study the thermal desorption of two ammonium salts: ammonium formate and ammonium acetate from a gold surface and from a water ice substrate. Methods. Temperature-programmed desorption experiments and Fourier transform infrared reflection spectroscopy were conducted to investigate the desorption behavior of ammonium salts. Results. Ammonium salts are semi-volatile species releasing neutral species as major components upon desorption, that is ammonia and the corresponding organic acid (HCOOH and CH3COOH), at temperatures higher than the temperature of thermal desorption of water ice. Their desorption follows a first-order Wigner-Polanyi law. We find the first order kinetic parameters A = 7.7 ± 0.6 × 1015 s−1 −1 20 −1 −1 and Ebind = 68.9 ± 0.1 kJ mol for ammonium formate and A = 3.0 ± 0.4 × 10 s and Ebind = 83.0 ± 0.2 kJ mol for ammonium acetate. -
Sodium Iodide Spotlight 352 Compiled by Vinícius Rangel Campos Vinícius Rangel Campos Was Born in Niterói/RJ, Brazil in 1986
1186 SPOTLIGHT SYNLETT Sodium Iodide Spotlight 352 Compiled by Vinícius Rangel Campos Vinícius Rangel Campos was born in Niterói/RJ, Brazil in 1986. He This feature focuses on a re- received his Chemistry degree from the Universidade Federal Fluminense (UFF), Niterói/RJ, Brazil in 2009. He is currently in the agent chosen by a postgradu- final stages of his MSc. studies under the supervision of Professors ate, highlighting the uses and Anna Claudia Cunha and Vitor Francisco Ferreira in Organic preparation of the reagent in Chemistry at the Universidade Federal Fluminense. His research in- current research terest is focused on the design and synthesis of new bioactive com- pounds, such as quinone and 1,2,3-triazole derivatives. Instituto de Química, Universidade Federal Fluminense, UFF, CEP: 24020-141 Niterói, Rio de Janeiro, Brazil E-mail: [email protected] Introduction NaI R–I NaX + R–X acetone Sodium iodide (NaI) occurs as colorless, odorless or as a X = Cl or Br white crystalline solid; it is slightly hygroscopic, and a commercially available reagent. It is soluble in water, Scheme 1 alcohols, acetone, and other organic solvents and stable This reaction has been expanded to include the conversion under normal temperature and pressure (mp: 651 °C, of alcohols into alkyl halides by first converting the alco- d = 3.67 g/cm3).1 On a laboratory scale, sodium iodide hol into a sulfonate ester (tosylates or mesylates are usu- may be prepared by neutralizing a solution of sodium hy- ally used), and then performing the substitution.6 Other droxide or sodium carbonate with hydriodic acid.2 Sodi- applications using sodium iodide as reagent in organic um iodide is a very useful and versatile reagent for the synthesis have been reported. -
Revision of KS4 the Periodic Table for KS5 Chemistry - Worksheet
Revision of KS4 The Periodic Table for KS5 Chemistry - Worksheet 1. On the copy of the periodic table (next page) label the following: a. metals and non metals b. groups (with numbers) c. periods (with numbers) d. transition elements 2. How are elements in the periodic table ordered? 3. Find two examples where the mass number does not increase. 4. How many electrons does Magnesium have in its highest energy level? 5. How many electrons does Oxygen have in its highest energy level? 6. What do elements in the same group have in common? 7. What happens to reactivity in group 1 as you go down the group? 8. What happens to reactivity in group 7 as you go down the group? 9. Name 1 similarity and 1 difference between group 1&2 metals and the transition elements. 10. Write a word and symbol equation to show how sodium reacts with water. 11. If identical pieces of lithium and potassium were dropped into a bowl of water at the same time describe how their reactions would differ. 12. Complete the table with ticks to show which reaction will happen. Fluorine Chlorine Bromine Iodine Sodium fluoride Sodium chloride Sodium bromide Sodium iodide Extension Question Research the appearance and state of group 7 elements, use this knowledge to predict observation for the reaction in question 12. Revision of KS4 The Periodic Table for KS5 Chemistry Image credit to LeVanHan https://commons.wikimedia.org/wiki/File:Periodic-table.jpg Revision of KS4 The Periodic Table for KS5 Chemistry Revision of KS4 The Periodic Table for KS5 Chemistry - Worksheet (Answers) 1. -
The Summer Assignment Will Receive a GRADE on the First Day of Class – August 9
Bishop Moore AP Chemistry Summer Assignment June 2017 Future AP Chemistry Student, Welcome to AP Chemistry. In order to ensure the best start for everyone next fall, I have prepared a summer assignment that reviews basic chemistry concepts some of which you may have forgotten you learned. For those topics you need help with there are a multitude of tremendous chemistry resources available on the Internet. With access to hundreds of websites either in your home or at the local library, I am confident that you will have sufficient resources to prepare adequately for the fall semester. The reference text book as part of AP course is “Chemistry: The Central Science” by Brown LeMay 14th Edition for AP. Much of the material in this summer packet will be familiar to you. It will be important for everyone to come to class the first day prepared. While I review throughout the course, extensive remediation is not an option as we work towards our goal of being 100% prepared for the AP Exam in early May. There will be a test covering the basic concepts included in the summer packet during the first or second week of school. You may contact me by email: ([email protected]) this summer. I will do my best to answer your questions ASAP. I hope you are looking forward to an exciting year of chemistry. You are all certainly excellent students, and with plenty of motivation and hard work you should find AP Chemistry a successful and rewarding experience. Finally, I recommend that you spread out the summer assignment. -
Flight Through the Comet Chury's Dust Cloud Resolves Chemical Mystery 21 January 2020
Flight through the comet Chury's dust cloud resolves chemical mystery 21 January 2020 em. Hans Balsiger, was on board. A key finding from the measurements taken by this instrument was that there appeared to be a lack of nitrogen in Halley's coma—the nebulous covering of comets which forms when a comet passes close to the sun. Although nitrogen (N) was discovered in the form of ammonia (NH3) and hydrocyanic acid (HCN), the incidence was far removed from the expected cosmic incidence. More than 30 years later, researchers have solved this mystery thanks to a happy accident. This is a result of the analysis of data from the Bernese mass spectrometer ROSINA, which collected data on the comet 67P/Churyumov-Gerasimenko, called Chury for short, on board the ESA space probe Rosetta (see info box below). Risky flight through the comet Chury's dust cloud Less than a month before the end of the Rosetta A plume of dust from Comet mission, the space probe was just 1.9 km above 67P/Churyumov–Gerasimenko, seen by the OSIRIS Wide Angle Camera on ESA's Rosetta spacecraft on 3 the surface of Chury as it flew through a dust cloud July 2016. The shadow of the plume is cast across the from the comet. This resulted in a direct impact of basin, which is in the Imhotep region. Credit: dust in the ion source of the mass spectrometer ESA/Rosetta/MPS for OSIRIS Team ROSINA-DFMS (Rosetta Orbiter Sensor for Ion and MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Neutral Analysis-Double Focusing Mass Spectrometer), led by the University of Bern. -
Elephant Toothpaste Lab
Elephant Toothpaste Lab This is a guideline to help you write up a formal lab report. This is not to be used as the formals lab report. You do not have to turn this in. Purpose: To break down a compound and release the maximum amount of substance in an elemental form. Background: (Sample) Hydrogen peroxide is an extremely reactive substance with the symbol H2O2 (water is H2O). That extra oxygen atom makes hydrogen peroxide a powerful oxidizer and it is widely used in strong concentrations as an industrial bleaching agent. It is corrosive to human skin in concentrations above 8% but very useful as an antiseptic at lower concentrations such as 3%. Hydrogen peroxide readily decomposes into water (H2O) and oxygen gas (O2) in the presence of even trace amounts of a proper catalyst. Catalysts are chemicals that increase the rate of a reaction. It this case, the catalyst is being used to increase the rate of breakdown of H2O2. Just a few grams of the catalyst potassium iodide (KI) causes nearly all of the hydrogen peroxide in a 30% solution to rapidly decompose. Significant quantities of heat and oxygen gas are released during decomposition making this an exothermic (heat releasing) reaction that should be handled with care. A squirt of detergent lowers the solutions surface tension so that the oxygen produced forms tiny bubbles which combine to make a very large volume of foam. Add something about the strength of catalysts. You will need to look this up before coming to class. Question: Which catalyst concentration will supply the most oxygen, 2M or saturated potassium iodide solution? Hypothesis: I hypothesize _______________________________________________________ because _____________________________________________________________________________. -
SN2 Reactions of Alkyl Halides
SN 2 Reactions of Alkyl Halides OBJECTIVE To examine factors affecting the relative rates of the SN2 reaction of alkyl halides such as: • alkyl halide structure • nature of the leaving group • properties of the nucleophile • steric hindrance INTRODUCTION The alkyl halides play an important role in organic synthesis. They can be easily prepared from alcohols or alkenes, among other starting materials. They in turn can be used in the synthesis of a large number of functional groups. These syntheses are often carried out by nucleophilic substitution reactions in which the halide is replaced by some nucleophile. These substitution reactions can occur in one smooth step, or in two discrete steps, depending primarily on the structure of the alkyl group. These mechanisms are known as SN2 and SN1: In this laboratory period we will spend some time looking at SN2 reactions. To get started, let's propose a mechanism for the reaction: − − CH3Br + HO ! CH3OH + Br (1) • The rate of this reaction is directly proportional to the concentration of both methyl bromide and sodium hydroxide. − Rate = k[CH3Br][OH ] (2) • The reaction proceeds with inversion of configuration. Any ideas? This mechanism was initially elucidated by Sir Christopher Ingold and Edward Hughes, in the 1930s. They interpreted the second-order kinetic behavior to mean that the rate-determining step is a bimolecular, concerted process. δ− δ− − − HO + CH3Br ! HO − − CH3 − − Br ! CH3OH + Br (3) transition state c 2011-2013 Advanced Instructional Systems, Inc. and Maria Gallardo-Williams 1 Therefore the following mechanism was proposed | the backside attack of the nucleophile, with the leaving group leaving in a concerted step. -
Chlorotrimethylsilane and Sodium Iodide
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Archive Ouverte en Sciences de l'Information et de la Communication Chlorotrimethylsilane and Sodium Iodide: A Remarkable Metal-Free Association for the Desulfurization of Benzylic Dithioketals under Mild Conditions Guangkuan Zhao, Ling-Zhi Yuan, Mouad Alami, Olivier Provot To cite this version: Guangkuan Zhao, Ling-Zhi Yuan, Mouad Alami, Olivier Provot. Chlorotrimethylsilane and Sodium Iodide: A Remarkable Metal-Free Association for the Desulfurization of Benzylic Dithioketals under Mild Conditions. Advanced Synthesis and Catalysis, Wiley-VCH Verlag, 2018, 360 (13), pp.2522-2536. 10.1002/adsc.201800437. hal-02394255 HAL Id: hal-02394255 https://hal.archives-ouvertes.fr/hal-02394255 Submitted on 4 Dec 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. FULL PAPER DOI: 10.1002/adsc.201((will be filled in by the editorial staff)) Chlorotrimethylsilane and Sodium Iodide: A Remarkable Metal- Free Association for the Desulfurization of Benzylic Dithioketals under Mild Conditions Guangkuan Zhao, Ling-Zhi Yuan, Mouad Alami* and Olivier Provot* BioCIS, Equipe Labellisée Ligue Contre le Cancer, Univ Paris-Sud, CNRS, University Paris Saclay, 92290, Châtenay- Malabry, France France Fax: (+33) 146-83-58-87, E-mail: [email protected] or [email protected] d: ((will be filled in by the editorial staff)) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201######.((Please delete if not appropriate)) Abstract. -
Sodium Iodide, ACS Safety Data Sheet According to Federal Register / Vol
Sodium Iodide, ACS Safety Data Sheet according to Federal Register / Vol. 77, No. 58 / Monday, March 26, 2012 / Rules and Regulations Date of issue: 05/05/2015 Revision date: 04/04/2018 Supersedes: 05/05/2015 Version: 1.1 SECTION 1: Identification 1.1. Identification Product form : Substance Substance name : Sodium Iodide, ACS CAS-No. : 7681-82-5 Product code : LC24645 Formula : NaI 1.2. Recommended use and restrictions on use Use of the substance/mixture : For laboratory and manufacturing use only. Recommended use : Laboratory chemicals Restrictions on use : Not for food, drug or household use 1.3. Supplier LabChem Inc Jackson's Pointe Commerce Park Building 1000, 1010 Jackson's Pointe Court Zelienople, PA 16063 - USA T 412-826-5230 - F 724-473-0647 [email protected] - www.labchem.com 1.4. Emergency telephone number Emergency number : CHEMTREC: 1-800-424-9300 or +1-703-741-5970 SECTION 2: Hazard(s) identification 2.1. Classification of the substance or mixture GHS-US classification Hazardous to the aquatic H400 Very toxic to aquatic life environment - Acute Hazard Category 1 Full text of H statements : see section 16 2.2. GHS Label elements, including precautionary statements GHS-US labeling Hazard pictograms (GHS-US) : GHS09 Signal word (GHS-US) : Warning Hazard statements (GHS-US) : H400 - Very toxic to aquatic life Precautionary statements (GHS-US) : P273 - Avoid release to the environment. P391 - Collect spillage. P501 - Dispose of contents/container to comply with local, state and federal regulations 2.3. Other hazards which do not result in classification Other hazards not contributing to the : None under normal conditions. -
Nucleophilic Substitution Reactions of Organic Halides
Exercise 10: Nucleophilic Substitution Reactions of Organic Halides Introduction: Substitution Reactions Substitution reactions are reactions where the two species involved exchange parts: Ex. Na C + Br C C + NaBr C There are two types of substitution reactions that commonly occur in organic chemical reactions, the SN2 and the SN1 reaction. They have different mechanisms which means their ability to occur is determined by factors like sterics around the alkyl halide, the choice of nucleophile used or even the solvent for the reaction. The SN2 Reaction (Substitution, Nucleophilic, Bimolecular) The SN2 type reaction is a one-step, concerted substitution process (make new bonds, break old bonds simultaneously). Both the alkyl halide and the nucleophile are involved (“bimolecular”) to determine the rate of reaction: Nuc X + X Nuc Factors that affect the SN2 Reaction: 1. Steric Congestion of Alkyl Halide -The more congested and sterically hindered the alkyl halide, the slower the reaction. Remember that alkyl halides have sp3 hybridized carbons, to which the halide is bonded. Fastest Slower Never CH3-X > RCH2-X > R2CH-X >>>>>>>>>>>>>>> R3C-X 2. The Leaving Group is what the halide is referred to in a substitution reaction and it is the group that must leave the alkyl halide. It is almost always expelled with a full negative charge in an SN2 reaction. The best leaving groups will be those that can best stabilize the anion (i.e. the weakest bases). Halides: I⊖ , Br⊖ > Cl⊖ >>> F⊖ (best) (worst) 3. The choice of solvent affects rate by affecting a reagent’s energy levels. Solvent molecules do what is called “solvation”, meaning they surround certain species in a reaction.