...liquids Evaporation | If the liquid in the mixture is more volatile (boiling point is lower) than the soluble solid, the soluble solid will remain while the liquid evaporates. The procedure employs the use of an evaporating dish and a Bunsen burner. | Crystallisation | Another method of dissolved solids from a liquid mixture (solution)The impure salt is dissolved in water at a high temperature to create a concentrated solution.The mixture is then cooled and the salt crystallises, leaving the impurity in the solution.This crystallised slat contains much less of the impurity than before. The salt can then be filtered and dried.Sugar cane industry. | Assess separation techniques for their suitability in separating examples of earth materials, identifying the differences in properties which enable these separations Yes, fractional distillation can separate a mixture of oxygen and nitrogen because they have similar (but not the same) boiling points. Could filtration successfully separate sand from a sand-salt mixture? No. Without water the salts in the sand and salt mixture will not separate out via filtration because filtration requires an insoluble solid plus a liquid mixture, which in this case would be salt + water Describe situations in which gravimetric analysis supplies useful data for chemists and other scientists * the process of determining the % by mass of one substance in a mixture * It is used to determine whether mining is economically feasible ...
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...photocatalysis is well established. Semiconductor photocatalyst (ZnO, TiO2, BiOCl, ZnS, WO3, and Fe2O4) can act as can act as sensitizers for light-induced redox processes due to their electronic structure [18-21]. The photocatalyst absorbs sunlight when the energy of the incident photons is equal or larger than the band gap (Eg) of the semiconductor. Thus, an electron is excited from the filled valence band (VB) of the photocatalyst into its empty conduction band (CB). When the photogenerated charge carriers are not utilized in photocatalytic reactions, they recombine within a few nanosecond to form luminescence or heat. . In presence of suitable scavenger or surface defect to capture the photo generated hole, recombination is prohibited and subsequent redox reactions may occur. The valence band holes are powerful oxidants (+1.0 to +3.5 V vs. NHE depending on the semiconductor and pH), while the conduction band electrons are good reductants (+0.5 to -1.5 V vs. NHE) [22-25]. Simultaneously, in aqueous medium, spontaneous adsorption occurs between water and pollutant and according to the redox potential of each adsorbate, conduction band electron transfer proceeds towards acceptor molecules, whereas a positive hole is transferred to a donor molecule. Each ion formed subsequently reacts to form the intermediates and final degraded products. The following features of photocatalysis warrants the applicability of process for the treatment of the contaminated aqueous pollutants [26-30, 1]. • Ambient...
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...lower the activation energy such that reactions can proceed at temperatures and pressures that are compatible with cellular processes. One of the major objectives of a previous laboratory was to use centrifugation to separate and isolate different components within the cell. The success of the separation procedure is commonly assessed by monitoring the enzymatic activity of enzymes that are characteristic of components expected within each faction. For example, succinic dehydrogenase (SDH) activity is commonly used as an indicator of mitochondrial purity: This inner mitochondrial membrane bound enzyme catalyzes the oxidation of succinate to fumarate within the Krebs cycle. SDH covalently binds the coenzyme FAD which accepts electrons during the oxidation of the succinate. In the cell, the reduced form of FAD, FADH, normally becomes reoxidized by iron-sulfur proteins in the electron transport chain to complete the catalytic cycle. The activity of this electron cascade can be monitored in vitro by the addition of artificial electron acceptors of higher reduction potential than FAD that show changes in absorption characteristics upon reduction. One useful artificial electron acceptor is 2,6-dichlorophenol indophenol (DCPIP) which shows...
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...metals contained are Zinc, Iron, Palladium, Cadmium, lead. The main metal compounds found in it is ZnS. b. The extraction of Zinc from Sphalerite follows: (the flow diagram is on the next page.) Step 1: Sieving The ore is firstly crushed and be able to be separated from the gangue. Step 2: Froth Flotation Since the concentration of zinc in natural ore is usually between 40%-50%. By using froth flotation, the percentage of ZnS rapidly increased. Step 3: Roasting High temperature is required to allow oxygen to react with Zinc sulphide. The following balanced equation shows the reaction, which is oxidation. The chemical balanced formula is stated below: 2ZnS (s) + 3O2 (g) → 2ZnO (l) + 2SO2 (g) Step 4: Extraction by using chemical reactions The use of carbon, mixed with ZnO under a hyperthermal environment produces the metal of Zinc with impurities. The chemical balanced formula is stated below: 2 ZnO (l) + C → 2 Zn (l) + CO2 (g) Step 5: Evaporation The ore changes its state as gas and leave the impurities behind. Step 6: Further purification Either fractional distillation or Electrolytic refining is applied to concentrate the impure zinc. c. The whole procedure of two extractions are very similar. At the beginning of extraction, both ores are needed to be ground by crushing to get rid of gangue. In the following stage, they use the same separation technique, froth flotation...
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...fluorine is a pale yellow gas, chlorine a greenish gas, bromine a red-brown liquid and iodine a black solid o Fluorine is small and leads to the repulsion between non-bonding electrons because they are so close together o The atoms get bigger as we go down the group because each element has one extra filled main level of electrons compared with the one above it |Halogen |Atomic number |Electron Arrangement |Electronegativity |Atomic radius nm |Melting point K |Boiling Point K | |Fluorine |9 |[He]2s22p5 |4.0 |0.071 |53 |85 | |Bromine |35 |[Ar]3d104s24p5 |2.8 |0.114 |266 |332 | Electronegativity - This is a measure of the ability of an atom to attract electrons, or electron density towards itself within a covalent bond o This depends on the attraction between the nucleus and bonding electrons in the outer shell, which depends on the balance between the nuclear charge and the distance between the nucleus and the bonding pairs plus the shielding effect of inner shells of electrons Melting and boiling points - Melting and boiling points involve weakening and breaking van der Waals forces only, the covalent bonds in the halogen molecules stay intact ...
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...40 INSTRUCTIONS: * Answer all the questions write neatly and legibly QUESTION 1 MULTIPLE CHOICE QUESTIONS 1. The symbols for sodium, carbon and oxygen… a) S, C and W b) S, C and O c) Na, C and O d) NA, C and O 2. The positive loaded parts in an atom… a) Electrons b) Protons c) Neutrons d) Molecules 3. We define matter as anything… a) That we can feel b) That we can see c) That has mass and takes up space d) That has weight 4. The name for NH3 is… a) Ammonia b) Nitrogen Hydroxide c) Natrium Hydroxide d) Ammonium Carbonate 5. The characteristics of non-metals are: i. Good insulator against heat ii. They are all gases iii. They are good conductors of heat iv. They are not good conductors of heat (A) iii and i (B) i and iv (C) ii and iv (D) iii and ii (5) QUESTION 2 MATCH COLUMN A WITH B AND WRITE THE ANSWER IN C COLUMN A | COLUMN B | COLUMN C | 2.1 Vertical columns on the periodic table | A. Unbreakable | I | 2.2 Negative loaded parts that moves around the nucleus of an Atom | B. Sodium Chloride | D | 2.3 An example of a compound | C. Fe2O3 | J | 2.4 The formula for rust | D. Electrons | C | 2.5 Smallest parts/particles of matter | E. Elements | G | 2.6 A diatomic molecule | F. Noble gases | H | 2.7 Pure substance that cannot be broken down into smaller Substances | G. Atoms | E | 2.8 Atom | H. O2 | A | 2.9 Elements in group 18 | I. Groups | F | 2.10 Table...
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...Electromagnetic fields are present everywhere around the atmosphere but are not visible. Electric fields are produced by the local build-up of electric charges in the atmosphere associated with thunderstorms. The earth's magnetic field causes a compass needle to orient in a North-South direction and is used by birds and fish for navigation.[ http://www.who.int/peh-emf/about/WhatisEMF/en/]. Now we will talk briefly about the atmospheric electromagnetic fields. There is always free electricity in the air and in the clouds, which acts by induction on the earth and electromagnetic devices. Experiments have shown that there is always free electricity in the atmosphere, which is sometimes negative and sometimes positive, but most generally positive, and the intensity of this free electricity is greater in the middle of the day than at morning or night and is greater in winter than in summer. In fine weather, the potential increases with altitude at about 30 volts per foot (100 V/m). The atmospheric medium, by which we are surrounded, contains not only combined electricity, like every other form of matter, but also a considerable quantity in a free and uncombined state; sometimes of one kind, sometimes of the other; but as a general rule it is always of an opposite kind to that of the Earth. Different layers, or strata, of the atmosphere, located at only small distances from each other, are frequently found to be in different electric states. The phenomena of atmospheric electricity...
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...Physics PHYSICS FORMULAE AND PRINCIPLES Fundamental quantities and SI units The standard units were set up by the international system of units, SI The fundamental quantities, there symbols and there SI units a listed below Quantity symbol SI unit & unit symbol Length l metre (m) Mass m kilogram (k g) Time t second (s) Temperature T Kelvin (k) Current I Ampere (A) Amt. substance mol mole 6.02 x 10 23 (molecules) Luminous intensity - candela (c d) MULTIPLES AND SUBMULTIPLES Multiples are larger than the base units and submultiples are smaller than the base units Multiples Symbol Prefix Meaning Example Deca d 10 1 0 Decameter Hecto h 102 100 Hectometer ...
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...CH 111: General Chemistry Dr. Ananda M The University of Dodoma, Tanzania Teaching Compendium on General Chemistry (CH 111) by Dr. AnandaMurthyM.Sc., M.Phil., Ph.D. Department of Chemistry, School of Physical Sciences, College of Natural &Mathematical Sciences, The University of Dodoma. UDOM- Study Material 2013-14 Page 1 CH 111: General Chemistry Dr. Ananda M Preface The importance of learning chemistry cannot be overemphasized. In this regard, all branches of chemistry contribute to the overall role that chemistry plays in daily life. The course content of CH 111 is designed to bridge the gap between the high school and the undergraduate chemistry, with respect to some fundamental topics in chemistry for first year chemistry students. This compendium will be helpful to the students, due to its relevance to the course content and will promote better understanding of the subject matter. It is intended to enable students to achieve the learning objectives and learning outcomes of CH 111 by being a quick reference to learners. The author of the compendium has presented the contents in a simplified manner by using various illustrations, including structures, tables, figures, and other relevant information to help the learner understand easily. This compendium will, to greater extent, help in understanding the basic concepts in chemistry. Dr. J.J. Makangara Senior Lecturer, Department of Chemistry, Former Dean, School of Physical Sciences, College...
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...residents will increase electricity tariff (TDL) since early July.He explains, to create electrical energy, the first star fruit commonly used as a vegetable is mashed to take water. Next, using soil media placed in a glass of mineral water is used, water is injected star fruit taste.Furthermore, each cup containing soil mixed with star fruit juice was associated with a series of copper wire and zinc plate, the electric current to flow.The result, electrical energy is created with a sizable voltage, ie up to 5 volts, enough to turn on the lights. The resulting voltage is also greater than the voltage of the battery stone fruit.According to him, electrical energy is created by starfruit has a high acidity level to be able to conduct ions and electrons are there on a piece of copper and zinc. Thus create an electric current.On average, 10 points starfruit is capable of creating an electric voltage up to 2.5 volts, equivalent to one dried fruit batteries. Even in his experience, the electrical energy of the star fruit vegetables can last up to one month old.Sunarto is also an electronic teacher in one school in this Magetan Bendo, hopes his invention will be...
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...will it start to condense? (A) 1250C (B) 1500C (C) 1750C (D) 2500C 2. How long does it take all the solid to melt? (A) 2.5 mins (B) 6.0 mins (C) 1.0 mins (D) 3.0 mins 3. 25cm3 of a gas X contains Z molecules at 150C and 75mmHg. How many molecules will 25cm3 of another gas Y contain at the same temperature and pressure? (A) 2Y (B) 2Z (C) Z (D) Y 4. What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen? (A) 36.0g (B) 8.0g (C) 72.0g (D) 16.0g [H = 1, O = 16] 5. A particle that contains 9 protons, 10 neutrons and 10 electrons is a (A) negative ion (B) positive ion (C) neutral atom of a non metal (D) neutral atom of a metal 6. Cancerous growth are cured by exposure to (A) γ -rays (B) β -rays (C) α -rays (D) x-rays 7. An oxide XO2 has a vapour density of 32. What is the atomic mass of X (A) 32 (B) 20 (C) 14 (D) 12 [O = 16] 8. Milikan’s contribution to the development of atomic theory is the determination of (A) charge on electron (B) positive rays (C) charge to mass ratio (D) cathode rays 9. Four elements W, X, Y, and Z have atomic numbers 2, 6, 16 and 20 respectively. Which of these elements is a metal? (A) X (B) W (C) Z (D) Y 10. An element X with relative atomic mass 16.2 contains two isotopes 16X 8 with relative abundance of 90% and X m8 with relative abundance of 10%. The value of m is (A) 16 (B) 18 (C) 12 (D) 14 11. + The diagram above represents the formation of (A) a metallic bond (B) an electrovalent bond (C) a covalent bond (D) a coordinate bond 12. Which...
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...reactions between iron ore slag and refractories Julien Zimmermann MSc PrograMMeS in engineering Materials Technology (eeigM) Luleå University of Technology Department of Applied Physics and Mechanical Engineering Division of Material Mechanics 2007:224 CIV • ISSN: 1402 - 1617 • ISRN: LTU - EX - - 07/224 - - SE Summary: For the fabrication of iron ore pellets at LKAB (Luossavaara-Kiirunavaara AB), one of the methods used is to sinter the pellets in a rotary kiln. This Kiln has a drift temperature of 1250°C in average. During this process a coating, causing the wear of the refractories materials, is formed, inducing expensive maintenance periods. The aim of this work is to find the reaction that takes place between the Slag and the bricks, in order to find the parameters that have to be changed to improve the bricks lifetime in the kiln. The use of bricks with higher alumina content is one of the solutions, but it is expensive. The influence of Alkalis and especially Na2O has been studied before in inert atmosphere. In this work it will be studied in air as well as the influence of the alumina content of the brick. Experiments were performed in air atmosphere, using powder samples that have been compressed into pellets. The devices used to characterize the reaction and the product of the reaction were: Kanthal furnace, X-ray diffraction (XRD), dilatometer, differential scanning calorimetry and thermogravimetry (DSC/TG) in-situ mass spectrometer, Scanning electron microscope...
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...Module 3 Waves and the Electromagnetic Spectrum Topic: Waves 1. What is a wave? A wave is vibration that travels and all waves are created by something vibrating. Waves transport energy but do not transport mass. 2. Describe the following terms associated with waves: a. amplitude height of wave b. wavelength length of a wave c. frequency number of waves per second (Hz) d. period how long a wave lasts when it arrives at a fixed point (measured in seconds) 3. What are radio waves? An electromagnetic wave of a frequency used for long distant communication. 4. Explain the difference between a transverse wave and a longitudinal wave, and give examples of each. In a longitudinal wave, the vibration travels in the same direction that wave travels. Examples of longitudinal waves include: Sound, p-waves (earthquakes) In a transverse wave, the vibration direction is perpendicular to direction that wave travels. Examples include: Light/electromagnetic, (radio, microwave, xray, etc.), water waves, swaves (earthquakes). The major difference between longitudinal and transverse waves is their direction. Longitudinal waves move left to right while transverse waves move up and down. 5. Compare and contrast: light waves vs. sound waves Light waves are transverse and sound waves are longitudinal. Light waves can travel through a vacuum but sound waves cannot. Speed of light is nearly 300 million m/s while sound has a speed of about 340 m/s...
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...Chemistry -Study of the composition, structure, properties, and interactions of matter. -Central Science. BRANCHES OF CHEMISTRY 1. Inorganic chemistry is the study of the chemical nature of the elements and their compounds (except hydrocarbons—compounds composed of carbon and hydrogen). Involves substance that do not contain carbon or substances from non-living things. 2. Organic Chemistry, branch of chemistry in which carbon compounds and their reactions are studied. A wide variety of classes of substances—such as drugs, vitamins, plastics, natural and synthetic fibers, as well as carbohydrates, proteins, and fats—consist of organic molecules. Study of all substance containing carbon in combination of hydrogen, oxygen, nitrogen and other elements. 3. Analytical chemistry is the science of separating complex materials into simpler ones and detecting and measuring the constituents. 4. Physical chemistry is fundamental to all chemistry and deals with the application of physical laws to chemical systems and chemical change. Concerned with theories and experiments that describes the behaviour of chemicals. 5. Biochemistry is the chemistry of living organisms and life processes. Cell: Compound 1. Protein 2. Carbohydrates - sugar 3. Nucleic acid – DNA, RNA 4. Lipids – fats SCIENTIFIC METHOD * A logical approach to the solution of the problem. STEPS: 1. Identify the problem 2. Gathering Information 3. Formulate hypothesis 4. Experimentation...
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...Mineral Sands: An Overview of the Industry Greg Jones1 ABSTRACT Mineral sands are different to most commodities, however they share similarities with other commodity types, such as the importance of quality constraints of iron ore and coal or the importance of physical properties of diamonds. The mineral sands industry consists of two principal product streams; titanium dioxide minerals – in the form of rutile, ilmenite and leucoxene; and zircon. The principal valuable heavy minerals (VHM) include ilmenite, leucoxene, rutile and zircon. Variations of other titanium minerals occur between the end members of ilmenite and rutile, including pseudo rutile and anatase. Most mineral sands deposits are found in unconsolidated fossil shorelines several hundreds of metres to tens of kilometres and occasionally hundreds of kilometres inland from the present coastline. Mineral sands orebodies essentially fall into two categories based on the mode of deposition: alluvial or aeolian. Alluvial deposits are further split into marine beach placers (or strandlines) and lacustrine heavy mineral (HM) accumulations. Exploration for mineral sands involves the positive identification of key criteria leading to the focus of exploratory surface sampling, augering and drilling. Assaying is primarily focused around determining the percentage of HM contained within a given sample. Other results of interest include clay fines, sand and oversize. Metallurgical/mineralogical assessment is often undertaken...
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