COVALENT COMPOUNDS Created By: Julio Cesar Torres Orozco
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On the Formation of Higher Carbon Oxides in Extreme Environments
Chemical Physics Letters 465 (2008) 1–9 Contents lists available at ScienceDirect Chemical Physics Letters journal homepage: www.elsevier.com/locate/cplett FRONTIERS ARTICLE On the formation of higher carbon oxides in extreme environments Ralf I. Kaiser a,*, Alexander M. Mebel b a Department of Chemistry, University of Hawaii at Manoa, 2545 The Mall (Bil 301A), Honolulu, HI 96822, USA b Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA article info abstract Article history: Due to the importance of higher carbon oxides of the general formula COx (x > 2) in atmospheric chem- Received 15 May 2008 istry, isotopic enrichment processes, low-temperature ices in the interstellar medium and in the outer In final form 22 July 2008 solar system, as well as potential implications to high-energy materials, an overview on higher carbon Available online 29 July 2008 oxides COx (x = 3–6) is presented. This article reviews recent developments on these transient species. Future challenges and directions of this research field are highlighted. Ó 2008 Elsevier B.V. All rights reserved. 1. Introduction tion has no activation energy, proceeds with almost unit efficiency, and most likely involves a reaction intermediate. However, neither In recent years, the interest in carbon oxides of higher complex- reaction products (kinetics studies) nor the nature of the interme- 1 + ityP than carbon monoxide (CO; X R ) and carbon dioxide (CO2; diate (kinetics and dynamicsP studies) were determined. On the 1 þ 1 + 3 À X g ) of the generic formula COx (x > 2) has been fueled by com- other hand, a CO(X R )+O2(X g ) exit channel was found to have plex reaction mechanisms of carbon oxides with atomic oxygen in an activation energy between 15 and 28 kJ molÀ1 in the range of the atmospheres of Mars [1–4] and Venus [5]. -
Unit: Stoichiometry Lesson: #10 Topics: Solvay Process
Unit: Stoichiometry Lesson: #10 Topics: Solvay Process The Solvay Process: A Case Study Many important industrial processes involve chemical reactions that are difficult to perform and still be economically feasible. In some cases, the overall process must follow a series of reaction steps. Sodium carbonate is a chemical that is needed in large amounts – it is used in the production of glass and soap. Historically, sodium carbonate was produced by burning plants or coal and mixing the ashes with water This method was both inefficient and very expensive because of the large amount of material that needed to be burned. The Solvay process was developed as a cost effective alternative. It involves a series of reaction steps and has a net reaction of: CaCO3 (s) + 2 NaCl (aq) Na2CO3 (aq) + CaCl2 (aq) A net reaction is determined by looking at the various reaction steps and eliminating any chemical that appears as both a reactant and a product in the various steps. These chemicals are known as intermediates. Step 1: Calcium carbonate (limestone) is decomposed by heat to form calcium oxide (lime) and carbon dioxide. CaCO3 (s) CaO (s) + CO2 (g) Step 2: Carbon dioxide reacts with aqueous ammonia and water to form aqueous ammonium hydrogen carbonate. CO2 (g) + NH3 (aq) + H2O (l) NH4HCO3 (aq) Step 3: The aqueous ammonium hydrogen carbonate reacts with sodium chloride to produce ammonium chloride and solid baking soda. NH4HCO3 (aq) + NaCl (aq) NH4Cl (aq) + NaHCO3 (s) Step 4: The baking soda is heated up and decomposed into sodium carbonate, water vapor and carbon dioxide. 2 NaHCO3 (s) Na2CO3 (s) + H2O (g) + CO2 (g) Step 5: The lime that was produced in the first step is mixed with water to produce slaked lime (calcium hydroxide). -
The Reaction of Calcium Chloride with Carbonate Salts
The Reaction of Calcium Chloride with Carbonate Salts PRE-LAB ASSIGNMENT: Reading: Chapter 3 & Chapter 4, sections 1-3 in Brown, LeMay, Bursten, & Murphy. 1. What product(s) might be expected to form when solid lithium carbonate is added to an aqueous solution of calcium chloride? Write a balanced chemical equation for this process. 2. How many grams of lithium carbonate would you need to fully react with one mole of calcium chloride? Please show your work. INTRODUCTION: The purpose of this lab is to help you discover the relationships between the reactants and products in a precipitation reaction. In this lab you will react a calcium chloride solution with lithium carbonate, sodium carbonate, or potassium carbonate. The precipitate that results will be filtered and weighed. In each determination you will use the same amount of calcium chloride and different amounts of your carbonate salt. This experiment is a "discovery"- type experiment. The procedure will be carefully described, but the analysis of the data is left purposely vague. You will work in small groups to decide how best to work up the data. In the process you will have the chance to discover some principles, to use what you have learned in lecture, and to practice thinking about manipulative details and theory at the same time. Plotting your data in an appropriate manner should verify the identity of the precipitate and clarify the relationship between the amount of carbonate salt and the yield of precipitate. Predicting the formulas of ionic compounds. Compounds like calcium chloride (CaCl2) and sodium carbonate (Na2CO3) are ionic substances. -
Solutions to Exercises
Solutions to Exercises Note: There may be more than one correct path to a correct answer. Chapter 1. Problem Solving 1. If your answer doesn’tagree with the published answer,possibilities include a) your answer may be incorrect, b) the published answer may be incorrect, c) both may be incorrect, d) both may be correct (i.e. there may be more than one correct answer), e) typographical error (answer out of place). 2. Terminology: chemistry is a noun (object), but could refer to an object of study or prac- tice, etc. As an object of study,chemistry could refer to what is expected to be known by a novice, all that is known, all that may be known, etc; as a practice, chemistry could refer to practical applications, theoretical principles, processes where substances change called chemical reactions, etc. The word reasonable might connote logic, understand- ing, ethical practice, demand, etc. One might logically conclude that the subject of chemistry should be understandable, or that the field of chemistry should be non-productive (if it is reasonable to assume that chemistry is harmful to the environment, say), etc. This example is not meant to be totally trivial. Communication involves common under- standing of terminology,construction (syntax) and meaning (semantics). Forexample, the word "add" may mean different things depending on the context; e.g. calculators (add twointegers), travelagents (add the mileage, add a flight, total the cost). Clear definitions and logical thinking are essential to science. 3. There seems to be an implicit assumption that Alice wants to go somewhere. If she doesn’tspecify anydestination, the Cat may give anarbitrary route. -
Amount of Substance
www.CHEMSHEETS.co.uk AMOUNT OF SUBSTANCE © www.CHEMSHEETS.co.uk 28-July-2020 Chemsheets AS 1027 1 1 - FORMULAE If you are serious about doing A level Chemistry, you MUST be able to write a formula without a second thought. It is the single most essential skill for an A level chemist. You have to know and be able to use the information on this page – you should not be looking it up. There is no data sheet with ion charges at A level. If you can’t write a formula in an instant, DROP CHEMISTRY NOW and choose something else. Elements Monatomic Simple molecular Ionic Metallic Giant covalent helium hydrogen There are no ionic The formula is just the The formula is just the elements!! symbol, e.g. symbol neon nitrogen magnesium diamond argon oxygen iron graphite krypton fluorine sodium silicon xenon chlorine nickel radon bromine iodine phosphorus sulfur Compounds Monatomic Simple molecular Ionic Metallic Giant covalent There are no monatomic Some common These have to be There are no metallic silicon dioxide compounds!! molecular compounds: worked out using ion compounds!! charges – you have to carbon dioxide know these at AS/A carbon monoxide level! nitrogen monoxide LEARN them ASAP. nitrogen dioxide sulfur dioxide Note these acids: sulfur trioxide hydrochloric acid ammonia sulfuric acid methane nitric acid hydrogen sulfide phosphoric acid Positive ions Negative ions Group 1 ions: Group 3 ions: Group 7 ions: Other common ions lithium aluminium fluoride nitrate sodium chloride sulfate Other common ions potassium bromide carbonate silver iodide hydrogencarbonate Group 2 ions: zinc hydroxide magnesium Group 6 ions: ammonium hydride calcium oxide hydrogen phosphate barium sulfide © www.CHEMSHEETS.co.uk 28-July-2020 Chemsheets AS 1027 2 TASK 1 – WRITING FORMULAS OF IONIC COMPOUNDS 1) silver bromide …………………………. -
Ni33nh3+3Nhi
Pure & Appi. Chem., Vol. 49, pp.67—73. Pergamon Press, 1977. Printed in Great Britain. NON-AQJEOUS SOLVENTS FOR PREPARATION AND REACTIONS OF NITROGEN HALOGEN COMPOUNDS Jochen Jander Department of Chemistry, University of Heidelberg, D 69 Heidelberg, Germany Abstract -Theimportance of non—aqueous solvents for the chemistry of haloamines is shown in more recent reaction examples. The solvents must be low-melting because of the general temperature sensitivity of the haloamines. They may take part in the reaction (formation of CH NI •CH NH (CH )2NI, NI-,.5 NH-, and NH0I.NH-)ormay e ner (ormation of I .quinuiilidin, 2 NI •1 trithylenediamine, [I(qunuclidine),] salts pure NBr, and compounds of the type R1R2NC103 with R1 and R2 =orgnicgroup or hydrogen). INTRODUCTION Non-aqueous solvents play an important role in preparation and reactions of nitrogen halogen compounds. Due to the fact, that all haloamines are derivatives of ammonia or amines, liquid ammonia or liquid organic amines are used as solvents very often. Liquid ammonia and the lower organic amines reveal, in addition, the advantage of low melting points (liquid ammonia -78, liquid monomethylamine -93.5, liquid dimethylamine -92, liquid tn-. methylamine -12k°C); these meet the general temperature sensitivity of the nitrogen halogen compounds, especially of the pure .lorganic ones. Ammonia and amines are very seldom inert solvents; they mostly take part in the reaction planned for synthesis or conversion of the haloamine. In case a reaction of the solvent is to be avoided, one has to look for a low melting inert solvent, for example methylene chloride (m.p. -
Isotopic Exchange Between Carbon Dioxide and Ozone Via O1D in The
GEOPHYSICAL RESEARCH LETTERS, VOL. 18, NO. 1, PAGES 13-16, JANUARY 1991 ISOTOPICEXCHANGE BETWEEN CARBONDIOXIDE AND OZONEVIA O(!D) IN THE STRATOSPHERE Yuk L. Yung, W.B. DoMore,and Joseph P. Pinto Abstract. We proposea novelmechanism for isotopic Table 1 exchangebetween CO 2 and0 3 vi•aO(ID) + CO2 -->CO_•* followedby CO3' --> CO2 + O(aP). A one-•ensior•al List of essentialreactions used in the photochemicalmodel. model calculation shows that this mechanism can account for The units for photodissociationcoefficients and two-body theenrichment in 180 in thestratospheric CO2 observed by rateconstants are s -1 andcm 3 s-l, respectively.The coeffi- Gatnoeta!. [1989],using the heavy 0 3 profile-observed by cientsfor photolysisrefer to nfid-latitudedimally averaged Mauersberger[1981]. The implicationsof this mechanism values at 30 kan. All molecular kinetic data are taken frmn for otherstratospheric species and as a sourceof isotopically DoMore etal. [1990], except otherwise stated. Rate heavyCO 2 in thetroposphere are briefly discussed. constantsforisotopic species are estimated byus. Q = 180. h•troduction Rla O3+ bY-->O2 + O(1D) Jla=7.4x10 -5 RecentlyGamo et at. [1989] reportedmeasurements of Rib O2Q+ hv-->O2 + Q(!D) Jlb=1/2 J la heavyisotopes of CO2 in the stratosphereover Japan. Let O R2a O(ID)+ M--->O+ M k2a= 2.0x 10-11 e ll0/T = 160 andQ = 180.The fiQ of stratosphericCO2, as defined R2b Q(1D) + M --->Q + M k2b= k2a in Gatno et at., was found to be 2O/oo(two parts in a R3 O(ID)+ CO2---->CO2 + O k3 = 7.4x 10-11 e 120/T thousand)greater than that of troposphericCO 2 at 19 km, R4a Q(1D)+ CO2-->CO Q + O k4a= 2/3k 3 and appearsto continueto increasewith altitudeup to the R4b O(ID)+ COQ-->CO2 + Q k4b= 1/3k 3 highestaltitude (25 km) where sampleswere taken. -
Sodium Laurilsulfate Used As an Excipient
9 October 2017 EMA/CHMP/351898/2014 corr. 1* Committee for Human Medicinal Products (CHMP) Sodium laurilsulfate used as an excipient Report published in support of the ‘Questions and answers on sodium laurilsulfate used as an excipient in medicinal products for human use’ (EMA/CHMP/606830/2017) * Deletion of the E number. Please see the corrected Annex for further details. 30 Churchill Place ● Canary Wharf ● London E14 5EU ● United Kingdom Telephone +44 (0)20 3660 6000 Facsimile +44 (0)20 3660 5555 Send a question via our website www.ema.europa.eu/contact An agency of the European Union © European Medicines Agency, 2018. Reproduction is authorised provided the source is acknowledged. Sodium laurilsulfate used as an excipient Table of contents Executive summary ..................................................................................... 3 Introduction ................................................................................................ 4 Scientific discussion .................................................................................... 4 1. Characteristics ....................................................................................... 4 1.1 Category (function) ............................................................................................. 4 1.2 Properties........................................................................................................... 4 1.3 Use in medicinal products ..................................................................................... 5 1.4 Regulatory -
Chapter 2, Section
Naming Simple Compounds Ionic Compounds Ionic compounds • consist of positive and negative ions. • have attractions called ionic bonds between positively and negatively charged ions. • have high melting and boiling points. • are solid at room temperature. Copyright © Houghton Mifflin Company. All rights reserved. 2–2 Salt is An Ionic Compound Sodium chloride or “table salt” is an example of an ionic compound. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings Copyright © Houghton Mifflin Company. All rights reserved. 2–3 Naming Ionic Compounds with Two Elements To name a compound that contains two elements, • identify the cation and anion. • name the cation first followed by the name of the anion. Copyright © Houghton Mifflin Company. All rights reserved. 2–4 Binary Ionic Compounds Type (I) An ionic formula • consists of positively and negatively charged ions. • is neutral. • has charge balance. total positive charge = total negative charge The symbol of the metal is written first followed by the symbol of the nonmetal. Copyright © Houghton Mifflin Company. All rights reserved. 2–5 Charge Balance In MgCl2 In MgCl2, • a Mg atom loses two valence electrons. • two Cl atoms each gain one electron. • subscripts indicate the number of ions needed to give charge balance. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings Copyright © Houghton Mifflin Company. All rights reserved. 2–6 Charge Balance in Na2S In Na2S. • two Na atoms lose one valence electron each. • one S atom gains two electrons. • subscripts show the number of ions needed to give Copyright © 2005 by Pearson Education, Inc. charge balance. Publishing as Benjamin Cummings Copyright © Houghton Mifflin Company. -
STUDENTS 2 SCIENCE Virtual Lab Experiment Precipitates
STUDENTS 2 SCIENCE Virtual Lab Experiment Precipitates An investigation of solubility and precipitation. A classroom Experiment in Kit Form for Grades 9-12 Brief Background: Students will learn the difference between reaction precipitates like the precipitation of Basic copper carBonate from the reaction of copper chloride and sodium carBonate and those that result solely from a change in solution soluBility (water vs. isopropanol). They will learn aBout precipitation in water treatment and purification and aBout the scientists who work to provide or maintain clean water for us. Additionally, students will learn that precipitates can sometimes Be redissolved By adding another chemical compound and thus carrying out an additional chemical reaction. Safety Students and teachers must wear properly fitting goggles as they prepare for, conduct, and clean up from the activities in the kit. Read and follow all safety warnings. Also review the Materials Safety Data Sheets. Students must wash their hands with soap and water after the activities. The activities described in this kit are intended for students under the direct supervision of teachers. Student kit packaged as 13 individual units for a class size of 26. Each student package is shared by 2 students. Items in each 2-student Ziploc bag: • (1) vial labeled “CuSO4” approximately 1/4 filled with cupric sulfate • (1) empty vial laBeled “CuSO4 Solution” • (1) 4-mL vial laBeled “CaCl2” containing small amount calcium chloride • (1) vial labeled “NaHCO3” (in red lettering) approximately 1/3 -
S1303, Sodium Hydroxide, Pellets, FCC
Scientific Documentation S1303, Sodium Hydroxide, Pellets, FCC Not appropriate for regulatory submission. Please visit www.spectrumchemical.com or contact Tech Services for the most up‐to‐date information contained in this information package. Spectrum Chemical Mfg Corp 769 Jersey Avenue New Brunswick, NJ 08901 Phone 732.214.1300 Ver4.06 29.September.2021 S1303, Sodium Hydroxide, Pellets, FCC Table of Contents Product Specification Certificate of Analysis Sample(s) Safety Data Sheet (SDS) Certification of Current Good Manufacturing Practices (cGMP) Manufacturing Process Flowchart Source Statement BSE/TSE Statement Allergen Statement GMO Statement Melamine Statement Nitrosamine Statement Animal Testing Statement Organic Compliance Statement Shelf Life Statement Other Chemicals Statement General Label Information – Sample Label General Lot Numbering System Guidance Kosher Certificate Halal Certificate Specification for Sodium Hydroxide, Pellets, FCC (S1303) Item Number S1303 Item Sodium Hydroxide, Pellets, FCC CAS Number 1310-73-2 Molecular Formula NaOH Molecular Weight 40.00 MDL Number Synonyms Caustic Soda ; Soda Lye Test Specification Min Max ASSAY (TOTAL ALKALI as NaOH) 95.0 100.5 % ARSENIC (As) 3 mg/kg CARBONATE (as Na2CO3) 3.0 % INSOLUBLE SUBSTANCES & ORGANIC MATTER TO PASS TEST LEAD (Pb) 2 mg/kg MERCURY 0.1 mg/kg IDENTIFICATION TO PASS TEST CERTIFIED KOSHER CERTIFIED HALAL APPEARANCE EXPIRATION DATE DATE OF MANUFACTURE MONOGRAPH EDITION Certificate Of Analysis Item Number S1303 Lot Number 1JG0041 Item Sodium Hydroxide, -
A Two-Step Graph Convolutional Decoder for Molecule Generation
A Two-Step Graph Convolutional Decoder for Molecule Generation Xavier Bresson Thomas Laurent School of Computer Science and Engineering Department of Mathematics NTU, Singapore Loyola Marymount University [email protected] [email protected] Abstract We propose a simple auto-encoder framework for molecule generation. The molec- ular graph is first encoded into a continuous latent representation z, which is then decoded back to a molecule. The encoding process is easy, but the decoding pro- cess remains challenging. In this work, we introduce a simple two-step decoding process. In a first step, a fully connected neural network uses the latent vector z to produce a molecular formula, for example CO2 (one carbon and two oxygen atoms). In a second step, a graph convolutional neural network uses the same latent vector z to place bonds between the atoms that were produced in the first step (for example a double bond will be placed between the carbon and each of the oxygens). This two-step process, in which a bag of atoms is first generated, and then assembled, provides a simple framework that allows us to develop an efficient molecule auto-encoder. Numerical experiments on basic tasks such as novelty, uniqueness, validity and optimized chemical property for the 250k ZINC molecules demonstrate the performances of the proposed system. Particularly, we achieve the highest reconstruction rate of 90.5%, improving the previous rate of 76.7%. We also report the best property improvement results when optimization is constrained by the molecular distance between the original and generated molecules. 1 Introduction A fundamental problem in drug discovery and material science is to design molecules with arbitrary optimized chemical properties.