Experiment to determine the ethanol content of wine

Experiment to Determine Ethanol Content of Wine The purpose of this experiment is to determine the ethanol content of each of the wines and compare the value determined to the value quoted on the label. These results can then be used to conclude which region is more accurate in quoting the value of the ethanol content of the wine. This experiment takes advantage of the fact that ethanol is less dense than water in solution. The density of ethanol at 20°C is 0.789 g/cm3 while the density of water at the same temperature is 0.998 g/cm3. It then follows that different solutions of ethanol and water will have different densities also, because the relative volume of ethanol increases and water decreases so the density of higher percentage ethanol solutions will be less than the density of lower percentage ethanol solutions. This occurs because water molecules are much smaller than ethanol molecule, meaning more water molecules can "pack" into a smaller volume than ethanol molecules, meaning there is more mass per unit volume of water compared to ethanol, meaning it has a higher density. In this experiment, solutions of ethanol in water were made up, going from 0% to 20%. These were then weighed, and the density of the ethanol was calculated. From this, a graph of percentage ethanol solution against density was made. This graphs later compared to the density of the wine, so

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Preparation of propanone from propan-2-ol

Date: 11/10/2011 Exp. No.: 23 Title: Preparation of propanone from propan-2-ol Aim: The aim of this experiment is to prepare propanone by oxidizing propan-2-ol with acidified potassium dichromate solution. Introduction: Ketones and aldehydes are important series in preparation of other compounds and they are commonly prepared by oxidizing alcohol which is done in this experiment. The experiment is an oxidation reaction where a secondary alcohol (propan-2-ol) is oxidized by acidified potassium dichromate. The reaction does not need to be heated but should be placed in an iced water bath as the reaction is highly exothermic. The product is propanone and no catalyst is needed for the reaction. The propanone is serparated from the reaction mixture by simple distillation and is purified using anhydrous cacium chloride. The equation of this reaction is as follow: Chromic acid is produced in situ by adding potassium dichromate (VI) with sulphuric acid and water. K2Cr2O7 + H2O + 2H2SO4 ? 2 H2CrO4 + 2 NaHSO4 The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. Chromic acid features chromium in an oxidation state of +6. It is a strong and corrosive oxidising agent. Apparatus and chemicals: Apparatus: Quick-fit distillation setup,

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Experiment to Determine Acidities of Wine. The purpose of this experiment is to determine the total and volatile acidities of each of the wines and compare them.

Experiment to Determine Acidities of Wine The purpose of this experiment is to determine the total and volatile acidities of each of the wines and compare them. Acidity is a major contributor to the taste of wines. This is especially important in white wines, because there are very little tannins found in it, so acidity can affect the taste of the wine much more than in red wines. In this experiment, 0.1M Sodium Hydroxide solution is needed for titrations. Because this is not a standard solution, it is first standardised using oxalic acid. In order to calculate the total acidity of the wine, a titration with 0.1M sodium hydroxide is carried out with a pH meter. The pH of the wine and sodium hydroxide solution is measured when a certain volume of NaOH is added each time, and a titration curve of volume against pH is plotted. The volume for the solution to reach a pH of 8.2 is recorded. This is because NaOH is a strong alkali and wine is a weak acid, so the pH lies more to the side of the alkali. A pH of 8.2 as the equivalence point is a value agreed on by winemakers. In order to calculate the total acidity of the wine, a representative acid must be used. This must be chosen because wine contains multiple different acids, which require different moles of NaOH to neutralise them. Tartaric acid was chosen as the representative acid for the wine, because it is thought to

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Design two experiments, one using titration and one using gas collection to show that H2SO4 is a dibasic acid.

Chemistry Practical Write-Up Aim: Design two experiments, one using titration and one using gas collection to show that H2SO4 is a dibasic acid. Gas Collection Experiment Prediction: If H2SO4 is dibasic it should give off a volume of hydrogen molecules, equal to the volume of H2SO4 used, below I have calculated how much gas to expect: H2SO4 + Mg › MgSO4 + H2 H2SO4 Concentration: 1 Mol/dm3 Volume: 0.025dm3 Moles: 1x0.025 = 0.025 H2 Moles: 0.025 0.025 * 24 Volume: 0.6dm3 Apparatus: Conical Flask, Magnesium, H2SO4, Bung, delivery tube, bowl of water, measuring cylinder. Diagram: Method: * Setup Apparatus as shown in the diagram. * Fill a conical flash with 25cm3 H2SO4. * Fill the measuring cylinder with water, making sure there are no bubbles, and turn it upside down in the water bath. * Drop the magnesium into the conical flask, and place the quickly place the bung on top. * The hydrogen gas will begin to displace the water in the measuring cylinder, wait until this stops, and record the results in a table like shown below, repeat until you have 3 results and calculate the average amount of gas evolved. Gas(dm3) - 1 Gas(dm3) - 2 Gas(dm³) - 3 Gas Average(dm³) To keep the results accurate we will keep all equipment and solutions used the same every time, we will do this experiment 3 times and take the average of the readings, and use this to see if

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The Synthesis Of Phenacetin From p-Acetamidophenol

CH1751B - EXPERIMENT 15 The Synthesis Of Phenacetin From p-Acetamidophenol Introduction: "Phenacetin is an analgetic and an antipyretic reagent which acts in the body by temporaririly inhibiting prostaglandin synthesis in the central nervous system". Aim: * To synthesise Phenacetin from p-Acetamidophenol and purify it by recrystallisation. * Analyse purity of Phenacetin produced, by comparing the melting point with the literature values, the appearance and the Infrared Spectrum. Method: Sodium metal (0.6g, cut into small pieces) was cautiously placed into a dry 100cm3 round flask by taking the flask to the "sodium" balance and placing the sodium directly into the flask. A dry reflux condenser was attached and industrial methylated spirits (IMS, 15cm3) was added. A vigorous reaction occurred for 5-10 minutes under reflux until most of the sodium had dissolved. Once the solution had cooled 3.8g of p-acetamidophenol was added. Through the top of the condenser ethyl iodide (3.0cm3) was introduced to the pale green mixture and the mixture boiled at reflux temperature (20-25°). Ethyl iodide was obtained from a burette in the fume hood few minutes before its use, due to its flammable nature and harmful vapour. A darkening green colouration occurred while p-acetanilide dissolved changing through to brown and then yellow. Once the reflux was completed 40cm3 of water was

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chemistry OCR-open book 2008

Section1: Discuss with the use of examples the main difference between Alpha decay and Beta decay: An alpha particle consists of 2 protons and 2 neutrons (He- nucleus), which is emitted as the nucleus looses 2 protons and 2 neutrons to become more stable. In this process a new chemical element is produced and this process is called transmutation, and this is a spontaneous reaction. For example the decay of Uranium-238 into Thorium- 234 E.g. 1 Beta decay: A beta- particle is a high energy electron, emitted when a neutron in the nucleus decay to form a proton and an electron. E.g. 1 E.g. 2 The differences between alpha and beta decay: Alpha decay Beta decay It's a form a nuclear fission reaction, where the atom splits in to two daughter nuclei. An energetic negative electron is emitted, producing a daughter nucleus of one higher atomic number and the same mass number. Alpha decay is restricted to heavier elements; an element only emits an alpha particle is it atomic number is less than 82. Beta particle is emitted when a heavy element decays with atomic number of above 82 decays. Alpha radiation reduces the ratio of protons to neutrons in the parent nucleus. A beta particle is emitted when there is too many neutrons, a neutron decays into a proton, an electron and an antineutrino. Difference between nuclear fission reaction and

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Making Aspirin

In this task we were asked to synthesise aspirin from salicylic acid (2 - hydroxybenzoic acid) and ethanoic anhydride (CH3COOCOCH3) in a laboratory scale and prepare a pure silver chloride sample from the solutions of silver nitrate (AgNO3) and sodium chloride (NaCl) of known concentrations. Now I am going to describe the preparation of these two items and estimate the purity of one of my samples. Preparation of aspirin: Now I am going to explain the preparation of the aspirin; Materials : (a) ethanoic acid (b) ethanoic anhydride (c) salicylic acid (d) water cooled condenser (e) filter paper (f) Buchner funnel (g) vacuum oven (h) melting point recorder machine etc. Procedure ) Firstly we mixed 5 ml of ethanoic acid with 5 ml of ethanoic anhydride in a 50 ml round bottomed flask. 2) After that we added 5 g of 2- hydroxybenzoic acid and a few anti - bumping stones . 3) Then we attached a water cooled condenser and reflux the mixture for 30 minutes over a Bunsen and gauze. 4) Then we pour the mixture slowly into 100 ml of cold water which is being stirred vigorously. 5) After that we removed the 2 - ethanoyloxybenzoic acid by filtration through a Buchner funnel. 6) Then we removed the product from the fume cupboard and dried it in a vacuum oven at about 80 degree Celsius. 7) Then we weight the dried product and recorded its melting point. Chemical reaction:

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An investigation into the efficiency of alcohols as fuels.

Joe Taylor 11T Chemistry coursework An investigation into the efficiency of alcohols as fuels Planning The aim of the experiment is to investigate the use of five alcohols as fuels. The combustion of alcohols is exothermic, meaning that when burnt they give off more heat than they take in. This makes them useful as fuels, and many countries are adopting alcohol fuels, for example Brazil. Therefore it seems useful and topical that the efficiency of the alcohols should be investigated. The alcohols methanol, ethanol, propan-1-ol and propan-2-ol will be tested. In order to evaluate the efficiency of these alcohols as fuels, their enthalpies will be investigated. Alcohols are perfect for testing, as they are all liquids with the same weight. Therefore weight is not a variable, and it is only the heat given off that is to need be considered. From previous organic chemistry studies the structures and formation of alkanes, alkenes and alcohols were known, along with the energy values for the bonds within alcohols themselves. This allowed for the creation of the bond energy table below. Bond Bond Energy (kJmol-1) C-H 435 O=O 497 C=O 803 H-O 464 C-C 347 C-O 358 These are the alcohol's formulae: Methanol: CH3OH Ethanol: C2H5OH Propan-1-ol: C3H7OH Propan-2-ol: C3H7OH Pentanol: C5H11OH Each of these reacts with Oxygen (0=0) in combustion For a pictorial

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Reactions of aldehydes and ketones. The purpose of this experiment is to compare some reactions of ethanal and propanone.

Date: 8/11/2011 Exp. No.: 25 Title: Reactions of aldehydes and ketones Aim: The purpose of this experiment is to compare some reactions of ethanal and propanone. Introduction: In this experiment, ethanal and propanone were chosen as they are relatively safe. The structures of the 2 compounds are as follow: Ethanal Propanone In this experiment, we are going to investigate the following reactions of these 2 compounds: . Addition 2. Condensation 3. Oxidation 4. Iodoform reaction Apparatus and chemicals: Apparatus: Safety spectacles, hot water bath, cold water bath, test tubes, beakers Chemicals: Saturated hydrosulphite solution , 2,4-dinitrophenylhydrazine solution, 0.1M potassium dichromate solution, 1M sulphuric acid, Fehling's reagent (Fehling solution A + Fehling solution B), 0.05M Silver nitrate solution, 2M sodium hydroxide solution, 2M ammonia solution, iodine solution 10% (in KI(aq)) Procedures: Part 1: Addition reaction with sodium hydrogensulphite . About 2 cm3 of saturated sodium hydrogensulphite solution was added into a test tube. 2. The test tube was put into a cold water bath. 3. Similar volume of ethanal was added drop by drop into the test tube. 4. The experiment was repeated using propanone instead of ethanal. Part 2: Condensation reaction with 2,3-dinitrophenylhydrazine . About 1 to 2 drops of ethanal was added

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UV-Visible Spectrophotometry

Name: Chu Ka Ki Student No.: 50555542 Group: 1 Date: 17-02-2005 Experiment: 2 BCH 2004 Principle of Analytical Chemistry Lab Report (Report One) Title: UV-Visible Spectrophotometry Aim: To determine phosphate composition in cola beverages by UV-Visible spectrophotometry and pH titrimetry. Introduction: UV-Visible spectrophotometry is one of the most important methods for the chemical analyze. Ultraviolet-Visible spectroscopy or Ultraviolet-Visible spectrophotometry (UV/VIS) involves the spectroscopy of photons (spectrophotometry). It uses light in the visible and adjacent near ultraviolet (UV) and near infrared (NIR) ranges. In this region of energy space molecules undergo electronic transitions. The method is used in a quantitative way to determine concentrations of an absorbing species in solution, using the Beer-Lambert law: where A is the measured absorbance, I0 is the intensity of the incident light at a given wavelength, I is the transmitted intensity, L the length of the cell, and c the concentration of the absorbing species. For each species and wavelength, ? is a constant known as the extinction coefficient. The absorbance A and extinction ? are sometimes defined in terms of the natural logarithm instead of the base-10 logarithm. Methodology: Colorimetric Analysis: At the beginning, 4cm3 decarbonated cola was transferred into a 100cm3

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