...Determining the enthalpy of combustion of Magnesium Om Vora Ms. Mohoruk Lab Partner: Ujjwal Nambiar 4/25/16 IB HL Chemistry 11 Purpose: The purpose of this lab is to determine the molar enthalpy of combustion of Mg using Hess Law by manipulating three formulas, two of which will be found through the experiment and one value is already given. Materials: Refer to lab handout on the front of the page as no changes were made. Procedure: Refer to lab handout on the front of the page as no changes were made. Qualitative results: • Bubbles and vapor is released during the reaction of both Mg and MgO. • Solutions in the calorimeter got really hot after the mixing the two. Sign of exothermic reaction. • Small residue of...
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...Title: Experiment 2 Determination of the valency of the magnesium Objective: -To study the quantitative relationship between the amount of reactants and products of a reaction. -A known starting mass of magnesium and the measured collection of hydrogen gas will be used to determine the reaction stoichiometry and the valency of magnesium. - To identify the unknown X value in the chemical equation between magnesium and hydrochloric acid - To determine the valency of magnesium Introduction: Stoichiometry is the study of the quantitative relationship between amounts of reactants and products of a reaction (that is, how many moles of A react with a given number of moles of B). In this section, a known starting mass of magnesium and the measured collection of hydrogen gas will be used to determine the reaction stoichiometry. Magnesium reacts with hydrochloric acid to form hydrogen gases. The aim of this experiment is to determine the value of x in the following equation: Mg + X HCI → MgCIX + H2 A known amount of magnesium is reacted with a large excess of HCl, and the volume of H2 evolved is measured. As HCl is in excess, all the magnesium will be consumed, and the yield of both MgClX and H2 is dependent on the amount of magnesium used. A comparison of the amount of hydrogen produced with the amount of magnesium consumed will enable the X value to be determined. Apparatus and Materials: Magnesium ribbon, 0.5M Hydrochloric acid, Burette (50 cm3), Pipette (25...
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...Conclusion: This experiment aimed to find out the empirical formula of magnesium oxide. In order to determine the percentage composition and empirical formula of magnesium oxide, a 10cm piece of magnesium strip was placed inside a crucible and heated strongly with a bunsen burner, to react it with the oxygen in the air. The masses were measured before and after the reaction. Balanced equation for magnesium oxide: 2Mg + O2 2MgO (“Types of Reaction”) According to “Burning Magnesium”, after magnesium is heated and reacted with the oxygen in the air, it is suppose to form a white powder of MgO, which is exactly what is shown in table 1. The reason why this white powder was formed is because when heated magnesium gives up 2 electrons to O2 atoms. This reaction is an exothermic, gives off heat. In table 1, the observations were that it took a while till the crucible was touchable, and not as hot as it was before. Overall, Metal oxides are bases and they react with acids to neutralize them and this is why magnesium oxide is found in most ingredients for treating acid reflux. (“Types of Reaction”) As said in table 1, magnesium turns red and then lights up and catches fire,...
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...experiment is to determine the empirical formula of magnesium oxide from the results that you obtain by burning Magnesium. We can calculate the empirical formula by combining the masses of magnesium and oxygen. Before combining the Mg with oxygen we will weigh it and we will also weigh the product of the reaction, Magnesium Oxide. If magnesium is heated in open air, its reaction with oxygen is fast. We can slow down the reaction by limiting the supply of oxygen that reaches the magnesium; we do that by putting a cover on the crucible that contains the magnesium sample. magnesium + oxygen → magnesium oxide (a) 2Mg(s) + O2(g)⇒ 2MgO(s) magnesium + nitrogen →...
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...The Affects of Iron and Magnesium Deficiency on Lemma minor’s Photosynthetic Process Lucia Aguilar INTRODUCTION Photosynthesis is the process in which plants can convert light energy into chemical energy to fulfill all of the functions of life. Iron and magnesium are nutrients that play an important role in photosynthesis. Deficiency in either of these nutrients will lead to a change in the photosynthetic rate of plants such as Lemma minor (duckweed). Magnesium is a mobile nutrient that affects older plants before it affects younger plants. Iron is a fairly immobile nutrient that causes chlorosis, the yellowing of leaves due to inadequate amounts of nutrients, in the younger plants (Campbell and Reece, 2005) In this experiment with variable deficiencies of magnesium and iron in Lemma minor, magnesium and iron nutrient concentrations were varied to see what affect the concentration variation, away from the required, had on the rate of photosynthesis of Lemma minor. It was hypothesized that a lack in either magnesium or iron would cause a disruption in the rate of photosynthesis. It was hypothesized that deficiency in magnesium would cause the Lemma minor to be unable to reproduce in number and therefore result in a lower dry mass. The cause of this would be the magnesium’s characteristics of being mobile. Because the magnesium is mobile, the photosynthetic properties of the older plants will be the first to be affected resulting in an inadequate amount of energy which...
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...triphenylmethanol from benzophenone via Grignard reaction. The product will be isolated through extractions and purified by recrystallization. Reaction efficiency will be evaluated through percent yield, percent recovery, and the purity of the final product will be determined by IR, TLC, and mp determination. Chemicals: bromobenzene, magnesium turnings, diethyl ether, benzophenone, biphenyl, triphenylmethanol, iodine, 6 M HCl, brine, anhydrous MgSO4 or Na2SO4, 10:90 EtOAc/hexanes. Glassware and equipment: 100 mL RBF, air condenser, Claisen adaptor, 60 and 125 mL addition funnel, short stem glass funnel, two 50 mL Erlenmeyer flasks, 10 mL graduated cylinder, lab jack, crystallizing dish, magnetic stir bar. Techniques: reflux, extraction, vacuum filtration, recrystallization, TLC, mp, IR spectroscopy. Introduction In 1912 Victor Grignard received the Nobel prize in chemistry for his work on the reaction that bears his name, a carbon-carbon bond-forming reaction by which almost any alcohol may be formed from appropriate alkyl halides and carbonyl compounds. The Grignard reagent RMgBr is easily formed by redox reaction of an alkyl halide with magnesium metal in anhydrous diethyl ether solvent. R-Br + Mg → RMgBr The Grignard reagent can be viewed as an ionic species consisting of carbanion R-, with Mg2+ counterion and an additional Br- counterion. The carbanion R- is very reactive, and functions both as an extremely strong base and an extremely strong nucleophile. O Br ...
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...Magnesium – WECKT den Turbo in DIR! Fitness Umschau Leser wissen mehr: Magnesium gilt als einer der ganz wichtigen Turbos für viele Prozesse im Körper. Umso schlimmer, wenn wir den Turbo nicht jederzeit aktivieren können, weil Magnesium fehlt. Wie kann das sein, wo doch die Schöpfung für uns genügend Magnesium bereithält. Denn die ersten 16 Kilometer unserer Erdschicht besteht zu fast 2 % aus Magnesium. Und es kommt noch besser: die Konzentration des Magnesiums in Meerwasser ist noch viel höher. Beim Eindunsten von 1 Liter Meerwasser bleiben nämlich immerhin 5,5 Gramm ! Magnesiumsalze übrig und das wiederum sind 15 % des gesamten Meersalzes von 1 Liter Meerwasser. Also müsste man meinen – Magnesium ist in Hülle und Fülle vorhanden. Weit gefehlt! Unsere Böden – zumindest die ersten Meter, in denen unsere Pflanzen sich ihre Mineralien herausholen - sind Magnesium verarmt durch die zu intensive Bewirtschaftung. Und das Meersalz ist meistens so aufbereitet, dass nur noch Spuren von Magnesium enthalten sind. So kommt es, dass im menschlichen Körper ein Magnesium Mangel auftritt - und zwar zunehmend häufig. Jeder hat in seinem Bekanntenkreis jemanden, der mit Muskelkrämpfen zu kämpfen hat. Er war beim Arzt und der bestätigt durch Laborchecks: „Calcium und Magnesium Werte perfekt“. Aus Verzweiflung nimmt der dann aber dennoch mal ein paar Magnesium Tabletten – und siehe - da es wird besser. An was liegt das? Die Antwort ist einfach! Wir messen das Magnesium dort, wo...
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...Year 10 Science Semester Two Examination - 2012 TIME ALLOWED 15 MINUTES READING 1 HOUR AND 15 MINUTES WRITING Instructions to candidates: 1) Do not write or mark the examination booklet in any way during reading time. 2) Please check that, aside from this test booklet, you also have a multiple choice answer sheet and data sheet. 3) There are 14 pages in this booklet including this one. Please check to ensure that this is so. 4) Note that the time allocated for the examination is 75 minutes and that 70 marks have been allocated: this should give you a guide as to how much time you should spend on each section. The survey at the end of the exam should take you approximately five minutes. 5) There are 4 sections in this booklet: multiple choice, true/false, definitions and extended questions. 6) Graphic calculators must not be used. Dictionaries must not be used. An approved scientific calculator may be used. 7) If you finish early please do not waste your time: you only get examination time once so it should not be wasted. Check your work thoroughly: calculations, grammar and spelling. Re-read the questions and check your answers to ensure that you have actually answered the questions asked. 8) When the signal to write is given fill in your name, form and teacher details on this booklet (below) and on the multiple choice answer sheet before you begin answering any questions. 9) All answers in this booklet must be completed in pen. 10) All numerical answers to questions must...
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...humans. Not getting enough of the two things can cause a lot of problems, anywhere from dehydration, anemia, high blood pressure, and increased risk of infection. The functions and sources depend on the mineral. For example calcium, which is milk, cheese, yogurt, and orange juice builds bones and teeth and keeps them strong, it also slows down bone loss, and helps muscles work properly. The mineral iron, which is meat, fish, poultry, iron and grain carries oxygen to all parts of your body and keeps you from being tired. Another mineral is potassium, which is bananas, sweet potatoes, tomato juice, prune juice, and dark leafy greens, helps control your blood pressure, and allows nerves and muscles to work together. A mineral named magnesium, which is spinach, bran cereal, peas, almonds, cashews, and seeds keeps nerves and muscles strong, and helps your bones and teeth. Some of these minerals have things in common with the functions, but they all come from different sources. There are several functions of water in our body, one it distributing essential nutrients to cells, such as minerals, vitamins and glucose. Also Water removes waste products including toxins that the organs’ cells reject, and removes them through urines. As well as being an effective lubricant around joints water also regulates your body temperature. The main way to prevent dehydration is to drink plenty of water every day, but if you do get dehydrated there are several signs and effects of dehydration...
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...Hydrochloric Acid and Magnesium Introduction What is Rate of Reaction? The reaction rate or rate of reaction for a reactant or product in a particular reaction is intuitively defined as how fast a reaction takes place. For example, the oxidation of iron under the atmosphere is a slow reaction which can take many years, but the combustion of butane in a fire is a reaction that takes place in fractions of a second. In this case how fast Magnesium reacts with Hydrochloric Acid. The equation for the reaction is magnesium + hydrochloric acid magnesium chloride + hydrogen Mg(s) + 2HCl(aq) MgCl2(aq) + H2(g) This is the equation for the reaction which will occur during my experiment What am I investigating? I am investigating the rate of reaction when the concentration of hydrochloric acid is increased with magnesium. What I am expecting is when the concentration increases so to will the speed of the reaction backing up the collision theory. This will be timed and put into seconds on how fast I gather an amount of gas and from my results a graph will show this data. Method To measure how long it takes to gather the amount of gas I had to carefully measure out 50ml of Hydrochloric Acid in a measuring cylinder. I kept this the same throughout all of the experiments in order for a fair test. I then poured this into the conical flask. After this I folded the 10cm strip of Magnesium and dropped it into...
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...Quarterly Journal of Experimental Physiology (1986) 71, 467-473 Printed in Great Britain FREE INTRACELLULAR MAGNESIUM CONCENTRATION IN FERRET VENTRICULAR MUSCLE MEASURED WITH ION SELECTIVE MICRO-ELECTRODES L. A. BLATTER AND JOHN A. S. McGUIGAN Department of Physiology, University of Berne, Buehlplatz 5, 3012 Berne, Switzerland (RECEIVED FOR PUBLICATION 2 AUGUST 1985) SUMMARY The free Mg concentration ([Mg]i) was measured in ferret ventricular muscle using singlebarrelled Mg-sensitive micro-electrodes. The electrodes were calibrated in solutions containing the [K]i and [Na]i measured in this tissue. In thirteen measurements from seven experiments conforming to strict criteria for calibration and penetration the estimated mean [Mg]i was 04 mmol/l. This is to be regarded as an upper limit since it was estimated by linear extrapolation of the calibration curve. INTRODUCTION Ionized Mg plays an essential role in the regulation of a large number of cellular functions. It is a co-factor in many enzymatic reactions, influences tension development in muscle and modulates amongst others the ionic transport systems in mitochondria (see reviews by Gunther, 1977; Shine, 1979; and Ackerman & Nicholls, 1983). Despite its importance in cellular mechanisms, estimations of the free Mg ([Mg]i) by various methods range from 0- 1 mmol/l to 6 mmol/l (reviews: Flatman, 1984; Gupta, Gupta & Moore, 1984) mainly because of the lack of a simple direct method for its measurement. Direct measurement of...
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...The Grignard Reaction is the addition of an organomagnesium halide, the Grignard reagent, to a ketone or aldehyde to form alcohols1. Grignard reaction are important in organic chemistry because they are relatively easy to perform, and they are one of the few reactions that can form new carbon – carbon bonds. The purpose of this experiment is to synthesize the Grignard reagent, phenyl magnesium bromide, from bromobenzene, and using the synthesized Grignard reagent to react with benzophenone to form triphenylmethanol. Grignard reagents typically have a molecular formula of RMgX, where R is either an aryl or alkyl group and X is a halogen like bromine, chlorine or iodine. Grignard reagents are made by a reaction between an alkyl or aryl halide with magnesium metal. This...
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...Alkali metals Cations occur in wide variety of important chemicals The metals are all very reactive when pure – strongly reducing Their cations (with the exception of lithium) have low charge densities – often leads to good solubility and an ability to stabilize anions that can not be formed along with any other cation Alkali metal physical properties Element Li Na K Rb Cs Density (gcm-3) 0.53 0.97 0.86 1.53 1.87 Melting point (oC) 180 98 64 39 29 ∆Hatm (kJmol-1) 162 108 90 82 78 1 Reactivity towards Bronsted acids The alkali metals react even with weak Bronsted acids such as water – The rate of reaction depends upon the acidity of the medium 2Na + 2H2O 2Na + 2EtOH 2Na + 2NH3 2NaOH + H2 2NaOEt + H2 2NaNH2 + H2 – very slow reaction in absence of catalyst Alkali metals and liquid NH3 Alkali metals react very slowly with liquid ammonia – however, they typically dissolve rapidly in ammonia to form highly colored solutions Na(s) --(ammonia)--> Na(am) + e-(am) – fast 2e-(am) + 2NH3 2NH2- + H2 – slow in absence of catalyst 2 Sodide anions and electrides 2Na(s) + C12H24O6 [Na(C12H24O6)]+Na– complexing or chelating agent is used to stabilize the cation » Na- is the sodide anion. It is the most stable alkalide ion Other complexing agents have been used to form solid salts where e- is the anion – electrides Lithium Lithium is the most reducing of all the alkali metals – but not the most reactive Unlike the other alkali metals it reacts with nitrogen to form a nitride Used...
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...Antacid Aluminum and Magnesium ANTACIDS THAT CONTAIN BOTH ALUMINUM AND MAGNESIUM SALTS ONCE SEEMED IDEAL BECAUSE ONE INGREDIENT COMPLEMENTED THE OTHER. ALUMINUM SALTS, WHICH DISSOLVE SLOWLY IN THE STOMACH, START TO WORK GRADUALLY BUT PROVIDE LONG-LASTING RELIEF. THEY ALSO CAUSE CONSTIPATION. MAGNESIUM SALTS ACT FAST AND NEUTRALIZE ACIDS EFFECTIVELY. THEY CAN ALSO ACT AS A LAXATIVE. ANTACIDS CONTAINING BOTH INGREDIENTS SHOULD PROVIDE QUICK, LONG-LASTING RELIEF WITH LESS RISK OF DIARRHEA OR CONSTIPATION. HOWEVER, THE LONG-TERM SAFETY OF ANTACIDS CONTAINING ALUMINUM HAS BEEN QUESTIONED. PROLONGED USE MAY WEAKEN BONES BY DEPLETING THE BODY OF PHOSPHORUS AND CALCIUM. Calcium Carbonate CALCIUM CARBONATE, OR CHALK, HAS BEEN A MAINSTAY OF ANTACIDS FOR A LONG TIME. CALCIUM CARBONATE ACTS FAST AND NEUTRALIZES ACIDS FOR A RELATIVELY LONG TIME. ALSO, IT IS AN INEXPENSIVE SOURCE OF CALCIUM; AMOUNTS RANGE FROM 500 TO 1000 MILLIGRAMS PER TABLET OR DOSE. HOWEVER, PEOPLE CAN OVERDOSE ON CALCIUM. THE MAXIMUM DAILY AMOUNT SHOULD NOT EXCEED 2000 MILLIGRAMS UNLESS A DOCTOR HAS DIRECTED OTHERWISE. Sodium Bicarbonate ONE OF THE LEAST EXPENSIVE AND MOST READILY AVAILABLE ANTACIDS IS NO FARTHER AWAY THAN THE KITCHEN CABINET. SODIUM BICARBONATE, OR BAKING SODA, NEUTRALIZES ACID QUICKLY. THE BAKING SODA BURP IS A SIGN THAT THIS ANTACID IS WORKING; THE BURP IS CAUSED BY RELEASE OF CARBON DIOXIDE GAS, WHICH OCCURS WHEN THE ANTACID NEUTRALIZES THE ACID. Although sodium bicarbonate may provide...
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...use a lathe to the shape titanium it becomes finely divided and will pose a dangerous risk of fire and/or explosion (Meyer, 2010). This dangerous process can occur because finely divided titanium reacts with atmospheric moisture and can self-ignite (Meyer, 2010). The use of automatic sprinkler systems can quickly supply a great amount of water to the burning metal to keep the spread of fire to the room of origin rather than giving it time to spread throughout the entire facility (Meyer, 2010). Reference: Meyer, E. (2010). Chemistry of hazardous materials (5th ed.). Upper Saddle River, NJ: Prentice Hall. 12) When relatively small amounts of magnesium burn, the fires are extinguished using commercially available dry powder. The MET-L-X extinguisher, or dry sand/earth can be very effective in the extinguishment of a small magnesium fire...
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