DOCSLIB.ORG

Acid Chemistry By: Michael Wild, Matt Huber, Jasmine Gilbert and Dr

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Acid Chemistry By: Michael Wild, Matt Huber, Jasmine Gilbert and Dr Acid Chemistry By: Michael Wild, Matt Huber, Jasmine Gilbert and Dr. Faith Yarberry In this module the student will: Understand the concept of an Acid. Discover the differences between strong acids and weak acids. Learn the meaning of the term pH with respect to acid / base strength. Uncover what an indicator is and how it works. Identify the strength of an acid and a base in various household products via pH. Be able to define a buffer, prepare a buffer, and understand the purpose of a buffer. Acid Chemistry Page 1 Lesson 1: Strengths of Acids The Bronsted/Lowry Definition of an acid is: Acid – a substance that donates a proton. Proton – the description used for a hydrogen cation (H+) because once an electron is removed from a hydrogen atom, all that is left is a proton) Example: Hydrochloric acid HCl → H+ + Cl- When an acid is dissolved in water, hence aqueous (aq), the hydrogen cation is donated to the + water forming a hydronium ion (H3O ). + - Hydrochloric acid HCl (aq) → H3O + Cl Not all acids are created equally. Strong acid – an acid that dissociates entirely in water to produce a hydronium ion and an anion. The diagram below shows this relationship.1 Acid Chemistry Page 2 Weak acid – an acid that only partially dissociates in water to produce a hydronium ion and an anion. The diagram below shows this relationship.1 Weak acids reach a state of equilibrium. Equilibrium – The point where the concentrations of the reactants and the concentration of the products cease to change, but the reaction itself continues. (1) Initially all that is present are reactants. Acid Chemistry Page 3 (2) The reaction moves in a forward direction building the concentration of products. (3) As the concentration of the products build the reverse reaction begins to occur. (4) The forward and the reverse reactions occur simultaneously. The forward reaction continues to make product while the reverse reaction continues to make reactants. At some point the concentration of the reactants and those of the products will cease to change. This point is called equilibrium. Acid equilibrium constants (Ka) – indicate the degree to which an acid will dissociate. The 1 diagram below indicates the relationship between Ka and dissociation. Acid Chemistry Page 4 In the laboratory you are going to prove that the stronger the acid, the greater its reactivity due to the quantity of free H+. To do so, you will be reacting magnesium metal with hydrochloric acid and with acetic acid. You will be collecting the amount of hydrogen produced by each reaction. From the amount of hydrogen produced you will be able to identify the strength of the acid. (LAB 1) Following the lab put up the following table to prove that what they observed was not just a result for acetic acid and hydrochloric acid. The value for trichloroacetic acid is off due to the fact that this material is hygroscopic. Being hygroscopic the concentration of the original solution not likely to be near the 5.0 M region as with the other materials. + Acid Ka Volume of H Hydrobromic Acid 1 x 109 55.5 mL Hydrochloric Acid 1 x 104 57.5 mL 1 x 103 Sulfuric Acid -2 55.5 mL 1.02 x 10 Trichloroacetic Acid 2 x 10-1 43.5 mL Iodic Acid 1.7 x 10-1 ---- Chloroacetic Acid 1.4 x 10-3 46.0 mL Ascorbic Acid 8 x 10-5 ---- Acetic Acid 1.8 x 10-5 38.0 mL Propionic Acid 1.32 x 10-5 12.0 mL Water 1 x 10-7 ---- Phenol 1.3 x 10-10 ---- Sodium Hydroxide 1.58 x 10-14 ---- Possible questions: (1) What reason can you give as to why sulfuric acid generates nearly twice the volume of H+ compared to hydrochloric acid and hydrobromic acid even though all three are strong acids? (Structure) (2) What reason can you give as to why this method may not have worked for determining + the H content in iodic acid even though its Ka resides between that of trichloroacetic acid and acetic acid? (Structure) (3) What do the weak acids have in common that did react with magnesium? (Structure) Acid Chemistry Page 5 Volume of Volume of H Conc. of 2 Compound Compound Structure K Compound Generated in 4 Conc of H+ a Compound Used minutes Hydrobromic Acid HBr 1 x 109 0.50 M 10.00 mL 55.5 mL 0.437 M Hydrochloric Acid HCl 1 x 104 0.50 M 10.00 mL 57.5 mL 0.453 M O 1 x 103 Sulfuric Acid HO S OH 0.50 M 5.00 mL 55.5 mL 0.874 M 1.02 x 10-2 O Cl O Cl Trichloroacetic Acid C C 2 x 10-1 0.50 M 10.00 mL 43.5 mL ---- Cl OH Acid Chemistry Page 6 O Iodic Acid 1.7 x 10-1 0.50 M 5.00 mL ---- ---- O I OH O -3 Chloroacetic Acid CH2 C 1.4 x 10 0.50 M 10.00 mL 46.0 mL 0.362 M Cl OH HO HO Ascorbic Acid O O 8 x 10-5 0.50 M 5.00 mL ---- ---- HO OH O Acetic Acid 1.8 x 10-5 0.50 M 10.00 mL 38.0 mL 0.299 M H3C OH Acid Chemistry Page 7 H C 3 O Propionic Acid 1.32 x 10-5 0.50 M 10.00 mL 12.0 mL 0.0945 M CH2 C OH -7 Water H2O 1 x 10 0.50 M 5.00 mL ---- ---- OH Phenol 1.3 x 10-10 0.50 M 5.00 mL ---- ---- Sodium Hydroxide NaOH 1.58 x 10-14 0.50 M 5.00 mL ---- ---- Acid Chemistry Page 8 Lesson 2: pH and Indicators A method for describing the concentration of H+ in solution is pH. pH – a term used to describe the acidity of a solution through the detection of H+ concentration in solution A neutral solution has a pH of 7.0. pH’s below 7.0 indicate that the solution is acidic and pH’s above 7.0 indicate that the solutions is basic. See the diagram below.1 The pH of a solution can be determined using an indicator or pH probes. Of these methods the pH probe will give the greatest amount of accuracy regarding pH, but pH probes can be expensive. A much less expensive method for determining the pH of a solution requires the use an indicator. Indicator – A substance that changes colors depending on the pH of the solution. pH indicators can be substances such as chemical compounds, litmus papers etc… that when added in small quantities to a solution visually allow us to determine the relative acidity or basicity of a solution by undergoing a change in color. Indicators are usually, themselves, either a weak acid or base that detect the hydrogen ion concentration in solution. Below is a table of indicators, the color of that indicator below the lowest pH indicated, the range for which a color change will be detectable, and the color of that indicator above the highest pH indicated.2 Acid Chemistry Page 9 Color Below Color Above Indicator pH Range Lowest pH Highest pH Methyl violet Yellow 0.5 to 2.0 Violet Thymol Blue Red 1.2 to 2.8 Yellow Yellow 8.2 to 9.1 Blue Methyl Orange Red 3.1 to 4.4 Yellow Methyl Red Red 4.2 to 6.3 Yellow Bromocresol Green Yellow 3.8 to 5.4 Blue Alizarin Yellow 5.7 to 7.1 Red Red 11.0 to 12.4 Purple Bromothymol Blue Yellow 6.0 to 7.6 Blue Phenol Red Yellow 6.4 to 8.0 Red Cresol Red Yellow 7.0 to 8.8 Red Phenolphthalein Colorless 8.0 to 9.8 Red Thymolphthalein Colorless 9.3 to 10.5 Blue By using a combination of indicators it is possible to determine the relative pH. Lab #2. There are many plants that contain chemicals that can be used as natural pH indicators such as the anthocyanin compound family. Red cabbage is part of that anthocynanin containing family. These compounds will usually turn acidic solutions a red color, basic solutions a green-yellow color, and neutral solutions a purple color. Due to this result it is possible that one can use red cabbage to find the pH of a solution as seen in the photograph below. Acid Chemistry Page 10 At this point have the students bring household products for class the following day to test the pH of the solution in Lab 3. We have stated that the pH of the solution allows us to determine the concentration of the H+ in solution. What is the connection? pH = -log [H+] Your assignment tomorrow, is to determine the approximate H+ concentration in each of the household solutions studied today. 10-pH = [H+] The next day the students will come in with the H+ concentration determined. Ideally you should come in with the real H+ concentration of the solution (pH probe). That way the students can see that the indicator does a fairly good job of predicting the H+ concentration. Acid Chemistry Page 11 Lesson 3: Buffers Some solutions, called buffers, are remarkably resistant to changes in pH. Water is not a buffer, since its pH is very sensitive to the addition of acidic or basic species. A good buffer, again, is a system that will prevent drastic changes in pH. Buffers are usually solutions of a weak acid and their conjugate base.
Load more

Recommended publications
  • Bromothymol Blue
    Safety Data Sheet Bromothymol Blue 1. PRODUCT AND COMPANY IDENTIFICATION Product Name: Bromothymol Blue Synonyms/Generic Names: 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)bis[2-bromo-3-methyl-6-(1- methylethyl)phenol]S,S-dioxide sodium salt SDS Number: 116.00 Product Use: For Educational Use Only Manufacturer: Columbus Chemical Industries, Inc. N4335 Temkin Rd. Columbus, WI. 53925 For More Information Contact: Ward's Science 5100 West Henrietta Rd. PO Box 92912-9012 Rochester, NY 14692 (800) 962-2660 (Monday-Friday 7:30-7:00 Eastern Time) In Case of Emergency Call: CHEMTREC - 800-424-9300 or 703-527-3887 (24 Hours/Day, 7 Days/Week) 2. HAZARDS IDENTIFICATION OSHA Hazards: No known OSHA hazards. Target Organs: None Signal Word: Warning Pictograms: None GHS Classification: Acute toxicity, Oral Category 5 GHS Label Elements, including precautionary statements: Hazard Statements: H303 May be harmful if swallowed. Precautionary Statements: P312 Call a POISON CENTER or doctor/physician if you feel unwell. Potential Health Effects Eyes May cause eye irritation. Inhalation May be harmful if inhaled. Causes respiratory tract irritation. Skin May be harmful if absorbed through skin. Causes skin irritation. Ingestion May be harmful if swallowed. Revised on 01/07/2013 Page 1 of 5 NFPA Ratings HMIS Ratings Health 1 Health 1 Flammability 1 Fire 1 Reactivity 0 Reactivity 0 Specific hazard Not Available Personal E 3. COMPOSITION/INFORMATION ON INGREDIENTS EINECS# / Molecular Component Weight % CAS # Formula ELINCS# Weight Bromothymol Blue 100 34722-90-2 N/A C27H27Br2NaO5S 646.36 g/mol 4. FIRST-AID MEASURES Eyes Rinse with plenty of water for at least 15 minutes and seek medical attention if necessary.
    [Show full text]
  • Toxicological Evaluation of Certain Veterinary Drug Residues in Food
    WHO FOOD ADDITIVES SERIES: 69 Prepared by the Seventy-eighth meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA) GENTIAN VIOLET page 3-34 Toxicological evaluation of certain veterinary drug residues in food , 2 7 The summaries and evaluations contained in this book are, in most cases, based on o. N unpublished proprietary data submitted for the purpose of the JECFA assessment. A registration es authority should not grant a registration on the basis of an evaluation unless it has first received i r e authorization for such use from the owner who submitted the data for JECFA review or has received the data on which the summaries are based, either from the owner of the data or from es es S a second party that has obtained permission from the owner of the data for this purpose. v i t i Add d World Health Organization, Geneva, 2014 oo F O O 6 1 H 0 W 2 GENTIAN VIOLET First draft prepared by Mr John Reeve 1 and Dr Susan Barlow 2 1 Science and Risk Assessment Branch, Ministry for Primary Industries, Wellington, New Zealand 2 Consultant, Brighton, East Sussex, England, United Kingdom 1. Explanation ........................................................................................... 4 2. Biological data ...................................................................................... 4 2.1 Biochemical aspects ....................................................................... 4 2.1.1 Absorption, distribution and excretion ................................... 4 (a) Mice ................................................................................
    [Show full text]
  • Identification of Typewriter Ribbons Charlotte L
    Journal of Criminal Law and Criminology Volume 46 | Issue 6 Article 15 1956 Identification of Typewriter Ribbons Charlotte L. Brown Paul L. Kirk Follow this and additional works at: https://scholarlycommons.law.northwestern.edu/jclc Part of the Criminal Law Commons, Criminology Commons, and the Criminology and Criminal Justice Commons Recommended Citation Charlotte L. Brown, Paul L. Kirk, Identification of Typewriter Ribbons, 46 J. Crim. L. Criminology & Police Sci. 882 (1955-1956) This Criminology is brought to you for free and open access by Northwestern University School of Law Scholarly Commons. It has been accepted for inclusion in Journal of Criminal Law and Criminology by an authorized editor of Northwestern University School of Law Scholarly Commons. IDENTIFICATION OF TYPEWRITER RIBBONS* CHARLOTTE L. BROWN AND PAUL L. KIRK Mrs. Charlotte L. Brown, a member of the staff of the School of Criminology, Univer- sity of California, has collaborated with Dr. Kirk in the research and presentation of several articles that have appeared in this Journal during the last few years. Two of these, which appeared in volume 45, dealt with methods of identifying various types of writing inks. Paul L. Kirk is Professor of Criminology at the University of California and has con- tributed periodically to this Journal during the last fifteen years. He is the author of "Crime Investigation" and numerous articles on various laboratory techniques in several branches of criminalistics.-EDITOR. In the examination of typewritten documents it is frequently desirable to determine that a particular ribbon was used, that two or more documents were prepared with the same ribbon, or that more than one ribbon was used in preparing a single docu- ment.
    [Show full text]
  • Gentian Violet S010
    Gentian Violet S010 Gentian Violet is used as staining solution for monochrome staining of microbes. Composition** Ingredients Gentian violet 0.500 gm Distilled water 100.000 ml **Formula adjusted, standardized to suit performance parameters Directions 1) Prepare a smear on a clear, dry glass slide. 2) Allow it to air dry and fix with gentle heat. 3) Flood the slide with Gentian Violet (S010). 4) Allow the stain to be in contact with the smear for 1-2 minutes. 5) Wash in slow-running water, just enough to remove excess of dye. 6) Flood the smear with Iodine, drain and flood again with Iodine for 1 minute. 7) Wash with decolourizer (alcohol) for about 5-15 seconds. Wash the slide to stop the action of decolourizer. 8) Flood with safranin for 1 minute, wash very lightly. 9) Blot dry and examine under oil immersion objective. Principle And Interpretation Gentian Violet is used as a simple stain where it can render the organisms violet. Besides this it can also be used in the Gram staining for distinguishing between gram-positive and gram-negative organisms. Earlier, Gentian violet was used as the primary stain in Grams staining method, subsequently crystal violet has replaced gentian violet because of the defined chemical nature of crystal violet. Quality Control Appearance Dark purple coloured solution. Clarity Clear without any particles. Microscopic Examination Gram staining is carried out where Gentian Violet is used as one of the stains and staining characteristics of organisms are observed under microscope using oil immersion lens. Results Fq`l,onrhshudnqf`mhrlr9Uhnkds Fq`l,mdf`shudnqf`mhrlr9 Qdc Nsgdqdkdldmsr9U`qhntrrg`cdrneqdcsnotqokd Storage and Shelf Life Store below 30°C in tightly closed container and away from bright light.
    [Show full text]
  • The Sensitizing and Indicator Action of Victoria Blue and Janus Green on the Flocculation Reaction for Syphilis
    In the case of sulphonamides, cultures resistant to sulphanilamide were resistant or partially resistant to the other members of this group with the exception of marfanil. Resistance once acquired seems to be permanent, and so far we have not been successful in reducing it in vitro. REFERENCES. ALBERT, A., FRANCIS, A. E., GARROD, L. P., AND LINNELL, W. H.-(1938) Brit. J. exp. Path., 19, 41. LANDY, M., LARKUM, N. W., OswALD, E. J., AND STREIGHTOFF, F.-(1943) Science, 97, 265. LEVADITI, C., AND MCINTOSH, J.-(1910) Bull. Soc. Path. exot., 3, 368. MACLEAN, I. H., ROGERS, K. B., AND FLEMING, A.-(1939) Lancet, i, 562. MACLEOD, C. M.-(1940) J. exp. Med., 72, 217. RAMMELKAMP, C. H., AND MAXON, T.-(1942) Proc. Soc. exp. Biol., N.Y., 51, 386. RUBBO, S. D., ALBERT, A., AND MAxWELL, M.-(1942) Brit. J. exp. Path., 23, 69. TILLETT, W. S., CAMBIER, M. J., AND HARRIS, W. H.-(1943) J. clin. Invest., 22, 249. THE SENSITIZING AND INDICATOR ACTION OF VICTORIA BLUE AND JANUS GREEN ON THE FLOCCULATION REACTION FOR SYPHILIS. F. M. BERGER. From the Public Health Laboratory, County Hall, Wakefield. Received for publication November 9, 1943. DEAN (1937) found that isamine blue could act as an indicator of the reaction between an antigen and its homologous antibody. The addition of the dye to a mixture of horse serum and dilute antiserum produced a precipitate which was easily visible because it took up all the dye from the supernatant fluid. Prof. P. L. Suther- land suggested the possibility of using isamine blue as indicator in serological tests for syphilis.
    [Show full text]
  • 1 Experiment 6 Determination of the Equilibrium Constant For
    Experiment 6 Determination of the Equilibrium Constant for Bromocresol Green Reading assignment: Chang, Chemistry 10th edition, Chapter 15: Acids and Bases, sections 1-5. Goals To determine the acid dissociation constant (Ka) for bromocresol green (BCG), an acid-base indicator. Discussion Acid-base indicators are often used to demonstrate the end-point of an acid-base reaction. Examples include phenolphthalein and the mixture of indicators used in universal indicator solution. Acid-base indicators are + – weak acids that dissociate into a hydronium ion (H3O ) and a conjugate base anion (In ). This dissociation can be represented through the following equation and equilibrium expression: +- +- [H3 O ][In ] HIn (aq) + H23 O (l) H O (aq) + In (aq) Ka = weak acidhydronium conjugatebase [HIn] indicatorion indicator In order for a compound to be a useful indicator, the acidic form (HIn) and the basic form (In–) of the indicator should differ in color. Since equilibrium in acidic solution favors the formation of HIn, this species is called the acidic form of the indicator. Likewise, the In– form is called the basic form since it is favored in basic solutions. An equilibrium mixture of the indicator will be colored according to the relative concentration of each form of the indicator. The position of the equilibrium and, therefore, the relative + + concentration of the two forms of the indicator will depend on the H3O concentration, [H3O ] or in shorthand notation [H+]. The absorption curve of an indicator at different pH values can be studied to determine the equilibrium constant of the indicator. In this experiment, we will determine the equilibrium constant of bromocresol green (BCG).
    [Show full text]
  • (A) Fill in the Blanks : (1) 10% Nacl Is Known As Brine. 1 (2) Very Fine Particles Mainly Scatter Blue Light
    MT 2017 ___ ___ 1100 MT - SCIENCE & TECHNOLOGY - I (72) - SEMI PRELIM - I : PAPER - 3 Time : 2 Hours Semi Prelim - I : Model Answer Paper Max. Marks : 40 SECTION - A A.1. (A) Fill in the blanks : (1) 10% NaCl is known as brine. 1 (2) Very fine particles mainly scatter blue light. 1 (3) The phenomenon of change in the direction of light when it passes 1 from one transparent medium to another is called refraction. A.1. (B) True or False : (1) False : Salts of strong acid and weak base are acidic in nature. 1 (2) True 1 A.2. Rewrite the following statements by selecting the correct alternative: (1) (d) Lichen 1 (2) (b) Ferrous chloride 1 (3) (c) passes without bending 1 (4) (a) 50º 1 (5) (a) increases 1 A.3. Answer the following in short : (Any 5) (1) Washing soda Baking soda 2 (i) It is sodium carbonate. (i) It is sodium bicarbonate or sodium hydrogen carbonate. (ii) It's molecular formula is (ii) It's molecular formula is . Na2CO3 10H2O NaHCO3. (iii) It is a crystalline substance. (iii) It is an amorphous powder. (iv) It is used in manufacturing (iv) It is used in bakery for soaps and detergent. making cakes and bread lighter and spongy. .. 2 .. PAPER 3 (2) (i) Baking soda is chemically known as sodium bicarbonate. 2 (ii) On heating, sodium bicarbonate decomposes to form sodium carbonate, water and carbon dioxide (CO2). (iii) The carbon dioxide produced is released due to which the cake becomes soft and spongy. (iv) Hence, baking soda is used to make cake spongy and soft.
    [Show full text]
  • LESSON 3 WHAT IS Ph? LESSON 3 : WHAT IS Ph?
    ENVIRONMENTAL CHEMISTRY AND OCEAN ACIDIFICATION LESSON 3 WHAT IS pH? LESSON 3 : WHAT IS pH? LESSON OBJECTIVES We are learning about how acids and alkalis are identified using the pH scale. 1 2 3 4 IDENTIFY DETERMINE EXPLAIN ANALYZE what the pH the pH of some various ways to the pH of water scale is and the everyday identify the pH samples using purpose for it substances of substances universal indicator pa IN PARTNERSHIP WITH SPONSORED BY LESSON 3 : WHAT IS pH? KEY VOCABULARY Acid A substance with a pH of less than 7 Alkali A substance with a pH of more than 7 (A soluble base) Base A substance which can neutralize an acid Litmus test A test for acidity or alkalinity using litmus Neutral Solution A substance with the pH of 7 pH A scale (0 -14) which measures the acidity or alkalinity of a solution. A solution or paper that changes color gradually over a range of pH. Universal indicator This is used to test the acidity and alkalinity of a solution. IN PARTNERSHIP WITH SPONSORED BY 1 LESSON 3 : WHAT IS pH? STARTER Take a look at these four images. Think about what substances are shown in each image. How would you categorize these images into two groups? Why did you choose to organize them this way? Explain. IN PARTNERSHIP WITH SPONSORED BY 1 LESSON 3 : WHAT IS pH? STARTER Scientists group these substances into acids and alkalis. Acids Alkalis Acids are corrosive substances. Alkalis are also corrosive substances. They are sour to taste. They feel very slippery when touched.
    [Show full text]
  • Thinking Like a Chemist About Acids and Bases Part V UNIT 6 DAY 10
    Thinking Like a Chemist About Acids and Bases Part V UNIT 6 DAY 10 What are we going to learn today? Explore Acid – Base Titrations Explore the concept of protonation and pKa Explore Behavior of Polyprotic Acids Acid Base Titration Why do a titration? You have a solution with an unknown property Unknown Concentration? Unknown Ka (Kb)? Both Slowly neutralize the solution by adding a strong base (acid) monitor the pH with each addition What do these plots tell you? How is the plot on the right different? Work with neighbors on Titration Discovery Activity Poll: Clicker Question The initial concentration of the HBr is: A) 7 M B) 0.7 M C) 0.007 M D) 0.0007 M E) 3.5 M Poll: Clicker Question The pKa for acetic acid is: A) 1.7 x 10-5 B) 1.6 x 10-9 C) 4.76 D) 8.32 E) 3.43 Chemical Equilibrium pH indicator Chemical Equilibrium pH indicator Bromothymol Blue, pKa = 7.1 Protonated form Deprotonated form yellow blue Poll: Clicker Question Chemical Equilibrium pH indicator Bromothymol Blue Bromophenol Blue has a pKa of around 7. When it is protonated (HA form) it is yellow, when it is deprotonated (A- form) it is blue. What color would in be in a solution in which the pH was 9? A. blue B. yellow C. green CH302 Vanden Bout/LaBrake Spring 2012 Polyprotic Acid Poll: Clicker Question Polyprotic Acid -4 Ka1 = 7.4 x 10 -5 Ka2 = 1.7 x 10 -7 Ka3 = 4.0 x 10 At pH = 2 how many of the acidic protons will be on the molecule? A.
    [Show full text]
  • Bromothymol Blue Indicator, 0.04-1% Aqueous
    SDS Safety Data Sheet 1. IDENTIFICATION Product Identifier: Bromothymol Blue Indicator, 0.04-1% w/v Aqueous Product Code(s): B1013, B1020, B1021 Synonyms: BTB, Sodium Salt Solution; 3,3’-Dibromothymolsulfonphthalein, Sodium Salt Solution Recommended Use: For manufacturing, industrial, and laboratory use only. Use as a laboratory reagent. Uses Advised Against: Not for food, drug, or household use. Supplier: Rocky Mountain Reagents, Inc. 4621 Technology Drive, Golden, CO 80403 Phone: (303) 762-0800 Fax: (303) 762-1240 Emergency Phone Number: For health emergency, call poison control: (800) 222-1222. 2. HAZARDS IDENTIFICATION Hazard Classifications: This product is classified as not hazardous under OSHA's Hazard Communication Standard, 29 CFR 1910.1200 (HCS) and the United Nations’ Globally Harmonized System of Classification and Labeling of Chemicals (GHS). However, all chemicals handled and used in the workplace should be treated with caution. Signal Word: Not applicable. Hazard Statements: Not applicable. Pictograms: Not applicable. Precautionary Statements: Prevention: Not applicable. Response: Not applicable. Storage: Not applicable. Disposal: Not applicable. Hazards Not Otherwise Not applicable. Classified: Toxicity Statement: Not applicable. Product: Bromothymol Blue Indicator, 0.04-1% w/v Aqueous Revision Date: 05/19/2016 1/7 3. COMPOSITION AND INFORMATION ON INGREDIENTS Component Common Name / Synonyms CAS# Chemical Formula % by Weight Water Water 7732-18-5 H2O ≥ 99.0 Bromothymol Blue, 3,3’-Dibromothymolsulfonphthalein, 34722-90-2 NaC27H27O5SBr2 ≤ 1.00 Sodium Salt Sodium Salt Trade Secret Statement: Not applicable. 4. FIRST AID MEASURES First Aid Procedures: Inhalation: Move to fresh air. If breathing is difficult, give oxygen. If not breathing, give artificial respiration. Call a physician if symptoms occur.
    [Show full text]
  • Practical Problems Revised Grading Scheme
    Student Code AAA-1 Practical Problems Revised Grading Scheme "Bonding the World with Chemistry" 49th INTERNATIONAL CHEMISTRY OLYMPIAD Nakhon Pathom, THAILAND Practical problems (official English version), 49th IChO 2017, Thailand 1 Student Code AAA-1 General Instructions. General Information In 0.1 mol dm-3 HCl, indicators are in the acidic form (HIn) only. In 0.1 mol dm-3 NaOH, indicators are in the basic form (In-) only. There will be no mark for the answer in the dotted line box. NOTE: Students are suggested to check the spectrophotometer before use by measuring the absorbance values of the instrument check solution at two different wavelengths, i.e., 430 and 620 nm. Spectrophotometer No. ________ is used throughout the experiment. Record the absorbance values of the instrument check solution A (at 430 nm) A (at 620 nm) Measured value ________________ ________________ Guided value 0.220 – 0.260 0.450 – 0.510 In case that the measured values are within the guided values, students can proceed with further experiments. If not, students can ask for assistance. Part a Absorbance measurement of an acid-base indicator (methyl orange) in strong acid and strong base 1. Pipette 1.50 cm3 of 2.00 10-4 mol dm-3 methyl orange indicator solution into a 25.00- cm3 volumetric flask, add 2.5 cm3 of 1 mol dm-3 HCl into the flask and make up to the volume using distilled water. Record the absorbance at 470 and 520 nm. 2. Pipette 2.00 cm3 of 2.00 10-4 mol dm-3 methyl orange indicator solution into a 25.00- cm3 volumetric flask, add 2.5 cm3 of 1 mol dm-3 NaOH into the flask and make up to the volume using distilled water.
    [Show full text]
  • Colloid Milium: a Histochemical Study* James H
    CORE Metadata, citation and similar papers at core.ac.uk Provided by Elsevier - Publisher Connector THE JOURNAL OF INVESTIOATIVE DERMATOLOOY vol. 49, No. 5 Copyright 1567 by The Williams & Wilkins Co. Printed in U.S.A. COLLOID MILIUM: A HISTOCHEMICAL STUDY* JAMES H. GRAHAM, M.D. AND ANTONIO S. MARQUES, M.D. Wagner (1), in 1866, first reported colloidreaction, with and without diastase digestion; milium in a 54 year old woman who showedcolloidal iron reaction, with and without bovine testicular hyaluronidase digestion for 1 hour at lesions on the forehead, cheeks and nose. In37 C; Movat's pentachrome I stain (2); alcian patients with colloid milium, the involvedblue pH 2.5 and 0.4 (3, 4); aldehyde-fuchsin pH skin is usually hyperpigmented, thickened,1.7 and 0.4 (4), with and without elastase digestion furrowed, nnd covered with multiple 0.5—5(5); Snook's reticulum stain; phosphotungstic acid hematoxylin stain (PTAH); Prussian blue re- mm dome-shaped, discrete papules. The shiny,action for iron; Fontana-Masson stain for ar- pink or orange to yellowish white translucentgentaffin granules; thiofiavine T fluorescent stain lesions have been likened to vesieles, but are(6, 7); Congo red; alkaline Congo red method firm and only after considerable pressure can(8); crystal violet amyloid stain; methyl violet a clear to yellow mueoid substance be ex-stain for amyloid (9, 5); toluidine blue (4); and Giemsa stain. The crystal violet and methyl vio- pressed from the papules. The lesions involvelet stained sections were mounted in Highman's sun exposed sites including the dorsum of theApathy gum syrup (5) which tends to prevent hands, web between the thumb and indexbleeding and gives a more permanent preparation.
    [Show full text]