Mole Ratios in a Chemical Reaction
Renee Buettel Period D4 Ms. Parziale /7/08 Lab #10: Mole Ratios in a Chemical Reaction Paul Bergin Abstract The main objective of this lab experiment was to balance the given chemical equation and to find the correct mole-to-mole ratio of it. The theoretical balanced equation was Pb(NO3)2(aq) + K2Cr2O7(aq) --> PbCr2O7(s) + 2KNO3(aq). In addition, the ratio of moles was one to one.and the correct mole-to-mole ration was one to one. The experimental results matched this ratio. The theory that was proven was that balancing equations give the correct mole ratio of a chemical equation. Introduction In a chemical equation, there are two sides. The chemicals on the tail end are called the reactants and the chemicals on the other side are called products. An example of this given by Coefficients (2008) is 2H2 + O2 --> 2H2O. In this example, "2H2 + 02" is the reactants and "2H2O" is the product. Also, "-->" is the sign for "yield." The big 2s in front of H2 and H2O are called coefficients. In this case, the first 2 indicates that there are 2 molecules of H2, which also means that there are 4 atoms of hydrogen in the reactant part of the equation. The other 2 signifies that there are 2 molecules of H2O as the product. This means that every molecule of H2O that contains 2 atoms of hydrogen contains 4 hydrogen atoms and 2 oxygen atoms. According to Chemistry Formulas (2005), the
Estimated heat distribution by convection in water
Estimated heat distribution by convection in water Introduction This report assesses the distribution of heat by convection in water to estimate the heat conductivity of water. The transfer of heat from a heating coil to a fluid is conduction but the heat transfer within the fluid is convection. This is basically fluid flow of particles arising from nature, heat, chemical or kinetics. The distribution of heat is assessed with various factors introduced. In this case a magnetic stirrer and a motor. This report presents an estimate of the effect of free and forced convention on the distribution of heat in water. Experimental method The apparatus were arranged as shown in fig. 1. A beaker of five litre capacity was places on a motor, four litres (4L) of cold water was put in a beaker. A heating coil and three thermometers were placed at various depths in the beaker of water and their various distances from the base of the beaker were recorded. Power was supplied to the motor and heating coil and at intervals of four minutes each; the temperatures on all three thermometers were read simultaneously. After four successful readings, the electricity supply was disconnected and the ambient temperature was recorded. This same procedure was repeated twice, the first with a magnetic stirrer and the next time without the magnetic stirrer but the motor operating. Distance from base
Nuclear Fusion as energy provider
For ?-decay, unstable atom emits an ?-particle, this can also apply to ?-decay. To distinguish ?-decay and ?-decay, here is a number of characteristic of each of the decay: relative charge, relative mass, nature, range, material to stop, deflection in electric field and magnetic field. ?-emission ?-emission Relative charge +2 -1 Relative mass 4 0.00055 Nature 2 protons + 2 neutrons (Helium nucleus) Electron Range 5cm 6m Material to stop Paper Aluminium(5mm thick)[] Deflection in electric field [2] Slightly towards negative terminal Greatly towards positive terminal Deflection in magnetic field[2] Slightly upwards Greatly downwards As an example, Bismuth can decay into Thallium and Polonium by emitting ?- and ?-particle respectively. For ?-decay of Bismuth: For ?-decay of Bismuth: The example above can show ?-particle is Helium particle while ?-particle is electron. Radioactive decay is different from fission reaction. Radioactive decay Fission . unstable . absorb 1 neutron 2. emit ?/?/?- particle 2. oscillate 3. become other elements 3. unstable 4.Fission (split) 5. give out 3 neutrons Fission reactions differ from radioactive decay both in the way that the reaction must be started and in the type of products that are formed [1]. Radioactive decay is a passive action, while fission is active. For radioactive decay, the atom is unstable;
The theory behind enthalpy changes
The theory behind enthalpy changes Exothermic reactions are most common, however, an important example of an endothermic reaction is photosynthesis in plants, where the energy supplied is from sunlight. Law of conservation of energy: Energy cannot be destroyed or created but only transferred from one form to another. The total energy of a system of reacting chemicals and surroundings remains constant. Enthalpy change is the term used to describe the energy exchange that takes place with the surroundings at a constant pressure and is given the symbol DH. Enthalpy is the total energy content of the reacting materials. It is given the symbol, H. DH = DH products - DH reactants The units are kilojoules per mole (kJmol-1) An exothermic enthalpy change is always given a negative value, as energy is lost to the surroundings. DH = -xkJmol-1 An endothermic enthalpy change is always given a positive value, as the energy is gained by the system from the surroundings. DH = + ykJmol-1. Standard enthalpy changes: standard conditions If we are to compare the enthalpy changes of a various reactions we must use standard conditions, such as known temperatures, pressures, amounts and concentrations of reactants or products. The standard conditions are: A pressure of 100kilopascals (102kPa) A temperature of 298K (25oC) Reactants and products in physical states, normal for the
Describe the construction, operation and application of distillation equipment used in industry
Faculty: Technology Assign/Activity Code: 306/02 Course Title: C&G 0603 - Process Technology Instructions for the use of this cover sheet (1) A cover sheet is required for every activity including presentations (2) Please complete all sections below (3) Staple the cover sheet to your activity Student name: Billy Whelton Unit(s): LEVEL 3 Unit 306: Distillation in the Process Industry Assignment/ Activity title: 02 - Distillation equipment & Their Safe Use Hand out date: 0-12-2007 Hand in date: 01-04-2008 Graded (Y/N) N Resubmission date for referred work: 08-04-2008 Student's comment on activity (if applicable): Student's Signature: ................................................ Date: ................. Assessment Grading Decision (by Assessor). Assessment decision following Verification. Activity designed by Assessed & graded by Key Skills Assessed by Name: Geoff Martin Name: Date: 28-06-05 Date: Internally Moderated by Internally Verified by Name: Name: Date: Date: You must store all marked activities in a portfolio (folder) for External Verification during the academic year. Grading descriptors PASS You have successfully completed all tasks and submitted all evidence as stated. Task Comments Pass Criteria Met Yes/No Grading Comments Overall Grade P/R Hand in date for referred work .................. Outcome 2:
Investigation into the chemist Fritz Haber
Coursework.info =) Research Project Chemist of choice: Fritz Haber Fritz Haber was born in the town of Breslau, Germany in early December 1868. His family was one of the oldest families in town, he was the son of Siegfried Haber who was a well know merchant in the town. Fritz studied at St. Elizabeth classical school in the town of his birth where he conducted many chemical experiments from a young age. From 1886 to 1891 Fritz studied chemistry at the University of Heidelberg under the academic advice of Robert Bunsen who had invented the Bunsen burner and also had help discover the elements cesium and rubidium. He also studied at the University of Berlin from guidance from A.W Hoffmann, and at the Technical School at Charlottenburg under Carl Liebbermann. Once he completed his studies at the universities he went and worked voluntarily for his father's chemical business as he was interested in chemical technology. He then went on to work at the under the eye off Professor Georg Lunge at the Institute of Technology in Zurich. After all this work he finally decided that he wanted to take up a scientific career and went to work with Ludwig Knorr at Hena for one and a half years to publish with him a joint paper on diacetosuccinic ester yet orthodox methods at the institute under Jena gave Haber little satisfaction. Still uncertain whether to devote himself to chemistry or
Determination of the Enthalpy Change of a Reaction
Determination of the Enthalpy Change of a Reaction Determine the enthalpy change of the thermal decomposition of calcium carbonate by an indirect method based on Hess' law. Using the proposed method of obtaining results, these values were gathered: Reaction 1: CaCO3(s) + 2HCl(aq) ?Cl2(aq) + CO2(g) + H2O(l) Experiment Number Mass of CaCO3 (g) Temperature Change (?) 2.50 2 2 2.55 2 1/6 3 2.50 2 1/4 4 2.53 2 1/6 5 2.47 2 µ 2.51 2.12 Reaction 2: CaO(s) + 2HCl(aq) ?Cl2(aq) +H2O(l) Experiment Number Mass of CaO (g) Temperature Change (oK) .30 9 1/2 2 .36 0 1/3 3 .46 1 4 .35 0 1/6 5 .40 0 1/2 µ .37 0.3 µ in both cases represents the mean of the data. Using the equation for enthalpy change: ?H = mc?T Where: m = Mass of liquid to which heat is transferred to (g) c = Specific heat capacity of aqueous solution (taken as water = 4.18 J.g-1.K-1) ?T = Temperature change (oK) We can thus determine the enthalpy changes of reaction 1 and reaction 2 using the mean (µ) of the data obtained. Reaction 1: ?H = 50 x 4.18 x -2.12 ?H = -443.08 This value is for 2.51g of calcium carbonate, not 100.1g which is its molecular weight. Therefore: ?H = -443.08 x (100.1 / 2.51) = -17670.2 J.mol-1. ?H = -17.67 kJ.mol-1. Reaction 2: ?H = 50 x 4.18 x -10.3 ?H = -2152.7 This value is for 1.37g of calcium oxide, not 56.1g which is its relative molecular
Test for reducing sugars (Benedict's Test)
Additional reading materials for Chapter 5: Nutrition Carbohydrates: Mono-, Di- and Polysaccharides Below is the flowchart to show the relationship between monosaccharides (simple sugars), disaccharides (complex sugars) and polysaccharides (e.g. starch and glycogen). Important things to note: (a) Glycosidic bonds are chemical bonds that hold / join molecules of monosaccharides together. (b) Chemical formulae of monosaccharides, disaccharides and polysaccharides. (c) Polysaccharides are macromolecules, meaning they are very large molecules (made up of many many small monosaccharide molecules joined together in straight or branched chains). (d) Examples of monosaccharides, disaccharides and polysaccharides. Test for reducing sugars (Benedict's Test) Given an unknown solution, you are to find out if it contains reducing sugars ... so you have to carry out the reducing sugar test (Benedict's test). NOTE: What are reducing sugars?? A reducing sugar (all monosaccharides and some disaccharides) will produce a brick-red ppt when boiles with Benedict' s solution. Non-reducing sugar: Sucrose Procedures: . To 2 cm 3 of the unknown solution in a test-tube, add an EQUAL VOLUME (that is the same volume as the unknown solution used: 2 cm 3 ) of Benedict's solution (blue). 2. Shake the mixture and heat it by immersing the test tube into a boiling water bath (beaker
Qualitative Analysis (A combined approach using spectroscopic and chemical analysis for structural identification of organic compound)
Student Name: Chan Yu Yan Maggie (Applied Biology) 22nd Nov, 2006 Student ID: 50920875 Group: B-2 BCH 2007 Principles of Organic Chemistry Experiment 8: Qualitative Analysis (A combined approach using spectroscopic and chemical analysis for structural identification of organic compound) Introduction In organic chemistry, the idenctification of organic compounds is a problem that is often encountered. As there are numerous of organic compounds of such wide variety in the world, identification is really difficult unless approached in a systematic and logical manner. To solve these problems, both spectroscopic and chemical techniques are useful. The general procedure for the identification of an organic compound consist of preliminary physical test, solubility test, qualitative elemental analysis, chemical characterization tests, spectroscopic analysis, literature search and further experimental comparisons. Objective: To identify the two unknown samples BL (molecular mass: 88.11 g, b.p.:76-78?C) and BS (molecular mass:122.17 g, m.p.:22-23?C) with known b.p or m.p and molecular mass by carry out different examinations, tests and spectroscopic analysis. Materials and Methods Procedure for preliminary physical examination The physical state, colour, shape and size, viscosity and odour of both the unknown solid and liquid were observed and recorded. For the
OBJECTIVE: To determine the content of iron in iron tablets by titration.
LAB: #3 DATE: 25th September, 2007 TITLE: Analyzing Iron Tablets OBJECTIVE: To determine the content of iron in iron tablets by titration. MATERIALS: . goggles and lab coat 2. 2 125cm3 conical flask 3. 1 250cm3 standard volumetric flask 4. 1 50cm3 burette 5. safety filler and pipette 6. 1 stand and clamp 7. filter funnel 8. Bunsen burner kit Chemicals . Iron tablets 2. 1.0moldm-3 sulphuric acid (200cm3) 3. 0.01moldm-3 Potassium Per Manganate 4. Distilled water/ wash bottles 5. soap solution PROCEDURES: Making a solution of the tablets . 5 iron tablets were weighed accurately, and then dissolved in about 100cm3 of 1.0 moldm-3 sulphuric acid in a conical flask. Some heating was required, but not more than the necessary needed to dissolve the tablets. 2. The mixture was filtered into a beaker, making sure that no solution was lost, then the conical flask was washed out with water and the washings were poured through the filter. 3. Finally, distilled water was poured over the residue and these washings we collected as well. The filtrate was then poured into a 250cm3 standard volumetric flask, washing out the beaker and adding washings to the standard flask. The mark was made up using distilled water. Titration
