DOCSLIB.ORG

Water of Crystallization Means? H (X + Y) Is Neutral Solution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Water of Crystallization Means? H (X + Y) Is Neutral Solution 14 øŒ‰vÚÛî¦ô¢Ù 13 è…šúÙñô¢ª 2019 email: [email protected] (X + Y) solution with inversal indicator. A: H 'X' is an acid H 'Y' is a base Water of Crystallization means? H (X + Y) is neutral solution. H Hence (X + Y) solution changes into green with universal solution. Acids, Bases and Salts 3) Washing Soda 4) Bleaching powder 8. What will happen if we test dry HCl with dry 4. Match the important chemicals given in column blue litmus paper? Why? Two Marks Questions A with the chemical formula given in colum B A: H Colour of blue litmus paper does not change. Column A Column B H Dry HCl do not release H+ ions. Hence is 1. What is a neutralization reactoin? Give one a) Plaster of paris i) Ca(OH) not behave as an acid. example. 2 1 9. A white powder 'A' is a mild non - corrosive b) Gypsum ii) CaSO4 ⎯ H2O A: Neutralization reaction: The reaction 2 base and is used in the preparation of between an acid and a base to give salt and c) Bleaching powder iii) CaSO4 2H2O cakes. When the powder is heated, it gives water is known as a neutralization reaction d) Quick lime iv) CaOCl2 another powder 'B'. The powder 'B' is Acid + Base → Salt + Water A: a-ii b-iii c-iv d-i recrystallized to get a substance 'C' which e.g.: HCl + NaOH → NaCl + H2O has detergent properties. Identify A, B and (aq) (aq) (aq) 5. Substance A changes the blue litmus paper into red colour. Substance B changes the C and also write balanced chemical equa- red litmus paper into blue colour. Now tions for the conversions of A and B. Writer answer the following questions. A: A → Baking soda (NaHCO3) D.V. Subba Naidu i) What is the name of reaction that takes Target-2020 B → Sodium carbonate (Na2CO3) Subject Expert place between A and B? C → Washing soda (Na2CO3H2O) ii) What are the compounds formed, if A Tenth Chemical equation 2. If a few drops of a concentrated acid acci- and B react with each other. 100 2 NaHCO3 → Na2CO3 + H2O + CO2 dentally spills over the sand of a student, A: i) A - Acid B - Base 100 Physical Science 10. Which product will form when CaO is dis- what should be done? The reaction between A and B is called solved in water? How do you find the A: Wash the hand immediately with plenty of neutralization reaction A: i) When Zinc reacts with HCl as well as nature of product? water and apply a paste of sodium hydro- ii) Salt and water are formed when A and B NaOH, Hydrogen gas is produced. A: When CaO (Quick lime), Calcium oxide is gen carbonate. react with each other. ii) Hydrogen gas puts off the flame with dissolved in water (H2O), Calcium hydrox- ide (Ca(OH) ) solution is formed. 3. Name the four chemicals that are obtained 6. What is the common observation made by 'pop' sound. 2 from common salt? you example while conducting the experi- 7. Solution 'X' turned blue litmus paper into CaO + H2O → Ca(OH)2 A: 1) Sodium hydroxide ment with Zinc and both HCl and NaOH red. Solution 'Y' turned phenolphthalein When red litmus paper is dipped in the solution, 2) Baking soda separately? How can you find it? solution into pink. Predict the result of test it turn blue. So, the solution is basic nature. Also give the common method to get relief solutions. e.g.: Vanilla essence 1 One Mark Questions ⎯ Mark Questions from the discomfort caused by the honey- 7. Which bases are called alkalies? Give an 2 bee sting. 1. What is the pH scale? example of alkali? 1. A Solution reacts with crushed egg-shells A: pH Scale: pH is defined as the negative A: Methanoic acid is present in bee sting. A: Water soluble bases are called alkalies. to give a gas that turns lime - water milky. logarithm of hydrogen ions [H+] concentra- When baking soda is rubbed on the affect- Examples of alkalies are NaOH, KOH etc. What is the nature of solutions? + ed part, it gives relief from pain. tion. pH = −log10 [H ]. 8. To prevent tooth decay we are advised to A: Acidic nature 5. If we keep a clean cloth along with finely brush our teeth regularly. The nature of the 2. Why does the soil of agricultural lands get 2. What is the colour of phenolphthalein tested for pH? chapped onion in plastic bag for few hours. tooth paste commonly used it? Now can we use this cloth as indicator? If indicator in alkaline medium? A: Plants required a specific pH range for A: Basic nature. Basic tooth paste neutralizes yes name the indicator? A: Pink colour their healthy growth. any acid which may be present on teeth. Acid A: We can use this cloth as indicator. This comes because of bacterial activity in mouth. 3. Write the colour of Methyl orange in 3. Write the molecular formula of common type of indicators are called 'olfactory indi- acidic solution. salt and baking soda which are widely used 9. Which substance is used in making toys, cators'. A: Red colour at home? materials for decoration and for making 6. What are olfactory indicators? surface smoth. Write its Chemical formula. A: Common salt - NaCl, Baking soda - 4. The pH values of fine different solutions A: Olfactory indicators are substance which A: Plaster of paris. Chemical formula is A, B, C, D and E are given as 1, 5, 7, 11 NaHCO3 have different odour in acidic and basic 1 and 13 respectively. Which is the 4. Name the acid present in honeybee sting. CuSO4 ⎯2 H2O. strongest acidic solution. A: Solution A Four Marks Questions 2. What is meant by 'water of crystallization' H Now cool the test tube and add 2 - 3 5. Write the formula for 'gypsum'? of substance? Describe an activity to show drops of water to the sample of anhy- A: CaSO . 2H O 1. With the help of pH scale answer the 4 2 the water of crystallization. drous copper sulphate. H We observe 6. With which salt, chlorine reacts to give following questions. A: Water of crystallization: The water of crys- the blue colour of copper sulphate bleaching powder as a product? tallisation is the fixed number of water mol- crystals is restored. H From this pH 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A: Ca(OH)2 ecules present in one formula unit of salt. activity, we conclude that somewater Sub- 7. What is the range of pH scale? stance P Q R S e.g.: CuSO . 5H O molecules are fixed in the blue coloured 4 2 A: 0 to 14 Acitivity: copper sulphate crystals. i) The pH value of Q is 6. So it is a weak 8. During indigestion, stomach produces H Take a few crystals of copper sulphate in 3. Draw a neat diagram showing a acid acid. Write the natures of solutions 'P' which acid excessively? a dry test tube. H Heat the dry crystals solution in water conducts electricity. Why and 'S'. A: HCl. strongly over the flame of a burner for the solution of sugar and glucose in water ii) Arrange the following solution from 9. When electricity is passed through a some time. H The water present in the do not conduct electricity? concentrated acid to concentrated aqueous solution of sodium chloride, it crystals are evaporated and the blue A: Acid solution have ions and movement of base. Milk, Hydrochloric acid, Sodium decompes to form sodium hydroxide. colour of salt turns to white. H We also these ions helps flow of current but glu- hydroxide, Baking Soda. What do you call this process? see tiny water droplets on the walls of cose and sugar solution do not have free ions iii) If we add the substances 'P' and 'S' in the test tube. and so current does not pass through them. A: Chloro - alkali process. equal quantities what is its nature? 10. Write the name of acid present in vinegar? CuSO4. 5H2O → CuSO4 + 5 H2O AC plug iv) Write the substance gives red colour Bulb Blue colour White colour 230 volt A: Acetic acid with methyl orange indicator. 11. Which colour do you observe, If a few A: i) P - strong acid, S - strong base. drops of NaOH sprinkled on pH paper? ii) Hydrochloric acid, milk, baking soda, Test tube holder Boiling tube A: Violet colour Sodium hydroxide. Water droplets Beaker Copper sulphate crystals 12. Arrange the following in the incresing iii) If 'P' and 'S' added to each other the Burner order of their pH values. solution formed is in neutral and its pH i) Weak acid ii) Weak base value is 7. dil. HCl solution iv) 'P' and 'Q' give red colour with methyl Graphite rods iii) Strong acid iv) Strong base orange indicator. Removing water of crystallisation Acid solution in water conducts electricity A: iii, i, ii, iv.
Load more

Recommended publications
  • Percent Composition of Hydrates
    Name _______________________ Class _________________ Date __________ Percent Composition of Hydrates You are a research chemist working for a company that is developing a new chemical moisture absorber and indicator. The company plans to seal the moisture absorber into a transparent, porous pouch attached to a cellophane window on the inside of packages for compact disc players. This way, moisture within the packages will be absorbed, and any package that has too much moisture can be quickly detected and dried out. Your company’s efforts have focused on copper(II) sulfate, CuSO4, which can absorb water to become a hydrate that shows a distinctive color change. When many ionic compounds are crystallized from a water solution, they include individual water molecules as part of their crystalline structure. If the substances are heated, this water of crystallization may be driven off and leave behind the pure anhydrous form of the compound. Because the law of multiple proportions also applies to crystalline hydrates, the number of moles of water driven off per mole of the anhydrous compound should be a simple whole-number ratio. You can use this information to help you determine the formula of the hydrate. To help your company decide whether CuSO4 is the right substance for the moisture absorber and indicator, you will need to examine the hydrated and anhydrous forms of the compound and determine the following: • the empirical formula of the hydrate, including its water of crystallization, • if the compound is useful as an indicator when it changes from the hydrated to the anhydrous form, and • the mass of water absorbed by the 25 g of anhydrous compound, which the company proposes to use.
    [Show full text]
  • By JARZD KIRTLAND MORSEI Coordinates of the Benzene Ring In
    VOL.. 13, 1927 PHYSICS: J. K. MORSE P789 All of the. foregoing indicates the importance of the X-ray diffraction study of liquids and adds. strong evidence in favor of the interpretation on the basis of a molecular space array. The existence of this array or cybotaxis is of fundamental interest in an understanding of physical phe- nomena in liquids. 1 Stewart and Morrow, Physic. Rev., 30, 9, 232 (1927). 2Adam, Proc. Roy. Soc., Alol, p. 452 (1922). THE STRUCTURE AND DIMENSIONS OF THE BENZENE RING By JARZD KIRTLAND MORSEI DEPARTMENT OF PHYSICS, UNIVERSITY OF CHICAGO Communicated November 15, 1927 In a previous paper2 the spherical atoms proposed by W. L. Bragg and W. P. Davey have been specialized and the cubic atom proposed by Lewis and developed by Langmuir extended to simple polyhedrons inscribable in spheres. It was shown in detail how these simple models could be built up into the various types of observed cubic and hexagonal lattices and how the lattice constants were geometrically related to the atomic radii. In the case of diamond and of graphite, it was found that these lattices could be built up of cubes having one corner (electron) shared in common and that the radius (half the body diagonal) was equal to 0.77 A in diamond and 0.75 A in graphite, giving a mean value for the radius of the carbon atom of 0.76 A over the extremely wide range of physical conditions between diamond and graphite. This paper is an account of the application of these ideas to the well- known problem of the structure of the benzene ring.
    [Show full text]
  • Salts of Therapeutic Agents: Chemical, Physicochemical, and Biological Considerations
    molecules Review Salts of Therapeutic Agents: Chemical, Physicochemical, and Biological Considerations Deepak Gupta 1, Deepak Bhatia 2 ID , Vivek Dave 3 ID , Vijaykumar Sutariya 4 and Sheeba Varghese Gupta 4,* 1 Department of Pharmaceutical Sciences, School of Pharmacy, Lake Erie College of Osteopathic Medicine, Bradenton, FL 34211, USA; [email protected] 2 ICPH Fairfax Bernard J. Dunn School of Pharmacy, Shenandoah University, Fairfax, VA 22031, USA; [email protected] 3 Wegmans School of Pharmacy, St. John Fisher College, Rochester, NY 14618, USA; [email protected] 4 Department of Pharmaceutical Sciences, USF College of Pharmacy, Tampa, FL 33612, USA; [email protected] * Correspondence: [email protected]; Tel.: +01-813-974-2635 Academic Editor: Peter Wipf Received: 7 June 2018; Accepted: 13 July 2018; Published: 14 July 2018 Abstract: The physicochemical and biological properties of active pharmaceutical ingredients (APIs) are greatly affected by their salt forms. The choice of a particular salt formulation is based on numerous factors such as API chemistry, intended dosage form, pharmacokinetics, and pharmacodynamics. The appropriate salt can improve the overall therapeutic and pharmaceutical effects of an API. However, the incorrect salt form can have the opposite effect, and can be quite detrimental for overall drug development. This review summarizes several criteria for choosing the appropriate salt forms, along with the effects of salt forms on the pharmaceutical properties of APIs. In addition to a comprehensive review of the selection criteria, this review also gives a brief historic perspective of the salt selection processes. Keywords: chemistry; salt; water solubility; routes of administration; physicochemical; stability; degradation 1.
    [Show full text]
  • Pp-03-25-New Dots.Qxd 10/23/02 2:38 PM Page 379
    pp-03-25-new dots.qxd 10/23/02 2:38 PM Page 379 HYDROGEN SULFIDE 379 HYDROGEN SULFIDE [7783-06-4] Formula: H2S; MW 34.08 Synonyms: sulfur hydride; sulfureted hydrogen Occurrence and Uses Hydrogen sulfide occurs in natural gas. It also is found in many sewer gases. It is a by-product of many industrial processes. Trace amounts of dis- solved H2S are found in wastewaters in equilibrium with dissolved sulfides and hydrosulfides. It also is found in volcanic eruptions, hot springs and in troposphere. The average concentration of H2S in the air is about 0.05 ppb. The most important applications of hydrogen sulfide involve the production of sodium sulfide and other inorganic sulfides. Hydrogen sulfide obtained as a by-product often is converted into sulfuric acid. It also is used in organic syn- thesis to make thiols or mercaptans. Other applications are in metallurgy for extracting nickel, copper, and cobalt as sulfides from their minerals; and in classical qualitative analytical methods for precipitation of many metals (see Reactions). It also is used in producing heavy water for nuclear reactors. Physical Properties Colorless gas; characteristic odor of rotten eggs; odor threshold 1ppm; sweetish taste; fumes in air; flammable gas, burns with a pale blue flame; refractive index at 589.3nm, 1.000644 at 0°C and 1 atm; density 1.539 g/L at 0°C; critical temperature 100.4°C; critical pressure 88.9 atm; liquefies at –60.7°C; solidifies at –85.5°C; velocity of sound 289 m/sec in H2S gas; slightly soluble in water (0.4% at 20°C); pH of a saturated aqueous solution 4.5; slight- ly acidic; diffusivity in water at 16°C, 1.77x105 cm2/sec; soluble in carbon disulfide, methanol, acetone; very soluble in N-methylpyrrolidinone and alka- nolamines (salt formation occurs: salt dissociates on heating); liquid H2S dis- solves sulfur and SO2.
    [Show full text]
  • Why Is Water Considered a Compound? Water Is a Considered a Compound, As It Is a Combination of Two Hydrogen Atoms and One Oxygen Atom
    Water Why is water considered a compound? Water is a considered a compound, as it is a combination of two hydrogen atoms and one oxygen atom. Water is also considered an amphoteric, meaning it acts both as an acid and a base as it produces H+ and OH- ions by self-ionization. As a chemical compound, its properties are: 1. In a water molecule, hydrogen and oxygen are combined in a fixed ratio by mass (1:8). 2. Components cannot be separated by physical means. 3. It has a definite and constant composition. 4. It has definite and constant melting point, boiling point, freezing point and density. 5. Water can react with metals to form the corresponding hydroxides. The ease with which the reaction occurs depends on the position of the metal in the reactivity series. Why is water called a universal solvent? Water is called the universal solvent since it is capable of dissolving a variety of different substances more than any other liquid. Water can dissolve more substances than any other compound because of its polar nature. The water molecules because of their composition – hydrogen with a positive charge on one side and oxygen with a negative charge on another, are able to attract other molecules easily. Water of crystallization: When crystals of certain salts are formed, they do so with a definite number of molecules of water that are chemically combined in a definite proportion. Water of crystallization is defined as the number of water molecules, chemically combined in a definite molecular proportion, with the salt in its crystalline state.
    [Show full text]
  • You Will Determine the Percentage of Water in a Hydrate and the Empirical Formula of a Hydrated Salt
    EXPERIMENT 7: HYDRATES Introduction: You will determine the percentage of water in a hydrate and the empirical formula of a hydrated salt. Background: Hydrates are chemical compounds that contain water as part of their crystal structure. This water is strongly bonded, is present in a definite proportion, and is referred to as water of hydration or water of crystallization. The formula of a hydrate consists of the formula of the anhydrous (without water) compound followed by a dot, then the number of molecules of water that crystallize with one formula unit of the compound, then the formula of water. Examples of hydrates are CaSO4 • 2H2 O Calcium sulfate dihydrate CoCl2 • 6H2O Cobalt (II) chloride hexahydrate Na2CO3 • H2O Sodium carbonate monohydrate Hydrates can be converted to the anhydrous form by heating: Hydrate Anhydride + Water CaSO4 • 2H2O CaSO4(s) + 2 H2O(g) Therefore, you can determine the percentage of water in a hydrate by determining the mass lost (amount of water driven off) when a known mass of hydrate is heated. Percentage of water = Mass of water lost x 100 Mass of hydrate In this experiment you will “heat to constant mass” in order to make sure that all the water of hydration is driven off. Since you cannot tell if all of the water has been driven off after the first heating or if some water still remains, the procedure of heating and cooling and weighing is repeated until two consecutive weighings are the same, within the limits of the uncertainty of the balance (± 0.02 g). Materials Needed Equipment Chemicals Pyrex test tube, holder, iron ring, triangle, tongs, CuSO4 • 5H2O, Crucible and cover or evaporating dish, cooling pad Unknown hydrate Setup: Part B Setup: Part A option 1 Los Angeles City College Chemistry 60 Procedure Part A: The behavior of a hydrate Place a scoop of CuSO4 • 5H2O (copper (II) sulfate pentahydrate) in a Pyrex test tube.
    [Show full text]
  • Studies in the Biochemistry of Micro-Organisms, 84
    Vol. 49 PERINEPHRIC AND INTERSCAPULAR FAT 563 mediate in type between those of the higher land It appears, therefore, that the fats of the tame animals and those of the reptiles and amphibia so rodents fed on.a suitable low-fat diet are generally far reported, in which the palmitic acid content is similar, but judged from the only detailed data somewhat reduced, being of the order of 10-20%, available there is reason to believe that the type of hexadecenoic acid being present in these fats to the fat elaborated by the tame rodents is not typical of extent of -1%.15 that of the wild varieties of the same species. Table 3 records the component acids ofthe rodents so far investigated. It is seen that the fats ofthe tame SUMMARY rabbit are on the whole similar to those of the other (tame) rodents. The palmitic acid content of the 1. The composition of the perinephric and inter- rabbit fats, however, is somewhat higher than that of scapular fats of an experimental rabbit has been the rat and guinea pig fats. The unsaturated C.8-acid investigated. content resembles that of the guinea pig rather than 2. The proportions ofthe component acids ofboth that ofthe rats, the guinea pig, however, elaborating fats were very similar, theperinephric fat being some- a considerable amount of polyethenoid C acids, what the more unsaturated. the amount being of the order of that present in the 3. Both fats were broadly similar to those ofother fats ofAmphibia and reptiles. The saturated acids of tame rodents, but differ appreciably from that the wild rabbit fat are likewise of the same order as recorded for a wild rabbit.
    [Show full text]
  • United States Patent Office Patented July 17, 1962 1
    3,045,050 United States Patent Office Patented July 17, 1962 1. 2 3,045,050 is reacted in the presence of a condensation agent, for METHOD OF PRODUCING AROMATIC example aluminum chloride. However, this method is SULPONES not very suitable for the production of ketones or com Cornelis Johannes' Schoot, Klaas Hinderikus Klaassens, and Johannes Jacobus Ponjee, Eindhoven, Netherlands, pounds which contain an aliphatic or cyclic ether or thio assignors to North American Philips Company, Inc., ether group. In these compounds, generally the ether New York, N.Y., a corporation of Delaware or thio-ether bond will be split as a secondary reaction No Drawing. Fied July 30, 1958, Ser. No. 751,885 by the action of the condensation agent, in the method in Claims priority, application Netherlands Aug. 14, 1957 accordance with the invention this disadvantage does not 10 Claims. (Cl. 260-607) occur, ether and thio-ether bonds are substantially not 10 attacked. This invention relates to a method of producing aro Suitable metal salts of sulfuric acid are the salts of the matic sulphones, characterized in that an aromatic com metals of the subgroups of the periods IV, V and VI and pound RH or RH or a mixture of these compounds, of the group VIII of the periodic table of the elements where R and R' can be equal or different and both rep and the salts of manganese, and particularly the salts of resent a benzene, naphthalene or thiophen nucleus which 15 the group comprising silver, zinc, cadmium, copper, carries at least one hydrocarbon radical or at least one mercury, tin and lead.
    [Show full text]
  • Paten'i'q Office
    Egg-tented July 179 i934 ‘ 3.9569947 . barren STATES PATEN'I‘Q OFFICE _ 1,966,947 I NONCAKING ivnxnn mn'mrznn can Eyer, Ludwigshafcn-on-the-Rhine, Gottwald Baetz, Oggersheim, and August Herterich, _Gerthc, Germany, assignors to I. G. Farben industrie Aktiengcsellschaft, Frankfort-on-the- ‘ . Main, Germany No Drawing. Application October 19, 1931, Serial No. 569,834. In Germany October 20, 1930 9 Claims. (01. 71-9) - 'The present invention relates to non-caking ,insu?icient for the complete conversion into ‘fer mixed fertilizers containing ammonium nitrate ric salts. V _ and a process for their production. ‘ It is not necessary to employ the additional Ammonium nitrate and many mixed fertilizers salts in a completely or partially dehydrated 55 containing ammonium nitrate have the objec-' state, but good results are also obtained by the tionable property of'hardening more or less employment of the completely hydrated salts, rapidly and strongly when stored, thereby losing provided a drying operation is applied after the 65 their capacity for being scattered. In order to addition of the iron or aluminium salts. obviate this objection it has already been pro-, . It is immaterial at which stage of the process it» posed to .add to the mixed. fertilizers small or in which form the said salts are added; for amounts of salts capable of combining with example they may be added in a dissolved or water of crystallization as for example mag solid form to the dissolved or fused fertilizers or 70 nesium salts or sodium salts; these additional mixed in the wholly or partly dehydrated form substances certainly prevent the hardening of with the ?nishedfertilizers.
    [Show full text]
  • United States Patent (19) 11 Patent Number: 5,679,817 Sakai Et Al
    US005679817A United States Patent (19) 11 Patent Number: 5,679,817 Sakai et al. 45) Date of Patent: Oct. 21, 1997 54 ALKYLENEDIAMINE-N,N'-DSUCCINIC OTHER PUBLICATIONS ACD RON () COMPLEX SALTSA lines (1992). 75 Inventors: Haruo Sakai; Takashi Sato; Toshitake Stereospecific Ligands and Their Complexes, Nealetal, vol. Yamakawa, all of Otake, Japan 7, No. 11, Nov. 1968, pp. 2405-2412. Synthesis and Complex-Forming Properties of Complexons 73 Assignee: Nitto Chemical Industry Co., Ltd., Derived from DiCarboxylic Acids v. Synthesis of Complex Tokyo, Japan ons Derived from Succinic Acid,Gorelov et al., Zhurnal Obshchei Kimii 49 (3), pp. 659-663. European Office Action dated Dec. 5, 1996. 21 Appl.... No.: 505.4505.46 Chemicalp Abstracts, vol. 101,No. 20, Abstract No. 182607n, 22 Filed: Jul. 21, 1995 p. 735 (1984). 30 Foreign Application Priority Data Primary Examiner-Porfirio Nazario-Gonzalez Attorney; Agent, or Firm-Cushman Darby & Cushman IP Jul. 25, 1994 JP Japan .................................... 6-92248 Group of Pillsbury Madison & Sutro LLP 51) int. Cl.6 .............................................. CO7F 15/02 57 ABSTRACT 52 U.S. Cl. .................................................. 556/48 58) Field of Search .............................................. 556/148 (S.S)-ethylenediamine-N,N'-disuccinic acid iron (DI) ammonium salt represented by the formula: (56) References Cited U.S. PATENT DOCUMENTS Hch co-ch.co. 5,238,791 8/1993 Tappe. (H): Fe3+NH FOREIGN PATENT DOCUMENTS NHCH(COCHCO 0532003 3/1993 European Pat. Off. wherein C* is an asymmetric carbon atom. This compound 2. A: E. Pat. Off. has a very high biodegradability and it is not accumulated in 554600 3/1993 J iny the environment even when used as a photographic process 0574829 2/1993 E.
    [Show full text]
  • An Examination of the Moisture Sorption Characteristics of Commercial Magnesium Stearate Vidya Swaminathan1 and Dane O
    AAPS PharmSciTech 2001; 2 (4) article 28 (http://www.pharmscitech.com). An Examination of the Moisture Sorption Characteristics of Commercial Magnesium Stearate Vidya Swaminathan1 and Dane O. Kildsig1 1Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47906 Submitted: August 22, 2001; Accepted: November 26, 2001; Published: December 3, 2001 ABSTRACT The objective of this study was to moisture content have received attention recently as characterize the moisture sorption of magnesium potential contributors to lubrication efficiency [3-7] . stearate and the morphological changes, if any, Four hydration states of magnesium stearate - the resulting from moisture sorption. Six samples of mono-, di-, and trihydrates and an anhydrous form - commercial magnesium stearate USP were examined. have been identified [3] . Moisture sorption isotherms were obtained at 25°C and The objective of the study was to characterize the 5% to 98% relative humidity (RH) using a moisture moisture sorption of commercial magnesium stearate. balance. Changes in crystal form resulting from The specific aims were (1) to characterize moisture moisture sorption were determined by x-ray diffraction. sorption and desorption isotherms at 25°C, (2) to There were differences in the shape of the isotherm, determine morphological changes, if any, resulting reversibility of moisture uptake, and shape of the from sorption of water, (3) to determine whether the hysteresis loop in the isotherms of crystalline and morphological changes are reversible, and (4) to amorphous magnesium stearates. The isotherm of determine whether moisture sorption characteristics can crystalline magnesium stearate was almost parallel to the be related to morphological changes. pressure axis until and RH of ~ 80%.The isotherm of the amorphous sample was characterized by continuous MATERIALS AND METHODS uptake of water over the entire range of RH.
    [Show full text]
  • INTRODUCTION Monosodium L-Glutamate Is Most Commonly
    [Agr. Biol. Chem., Vol. 28, No. 9, p. 646•`649, 1964] A New Crystalline form of Monosodium L-Glutamate By Hiromasa MARUYAMA, Tsuyoshi FUJIWARA and Kuniharu TAKENOUCHI Ajinomoto Co. Inc., Kawasaki Factory, Kawasaki Received March 19, 1964 A new crystalline form of monosodium L-glutamate, which is different from the known monoso- dium L-glutamate monohydrate crystal in external appearance, density, X-ray diffraction pattern, solubility, and water of crystallization, has been crystallized from ca. 73 weight per cent aqueous methanol solution at ca. 18°C. It was identified as the dihydrate from the determination of water of crystal lization based on Karl Fischer's method. The newly found crystals are extremely unstable in air, aqueous solution, and the mother liquor, because of rapid transformation into the stable monohydrate, whereas they can be kept in a considerably stable condition in absolute ethanol and acetone. INTRODUCTION 2. Procedure and Results Monosodium L-glutamate is most commonly (1) Crystallization obtained as the monohydrate, while it sometimes 1500 ml of absolute methanol and 300 ml of water crystallizes as the pentahydrate1) at temperatures were poured into a 21-flask. To the prepared ca. 80 weight per cent aqueous methanol, 200 ml of 37.5 weight below -0.8°C. The authors found that unstable per cent monosodium L-glutamate monohydrate aqueous crystals of monosodium L-glutamate dihydrate, solution is slowly added with stirring at room temperature, whose constitution was decided by quantitative ca. 18°C. When addition is finished, nothing appears in analysis of water of crystallization based on Karl the immediately solution.
    [Show full text]