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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Green Chemistry - greenhouse gases and the ozone layer

The 'Greenhouse effect' ? The greenhouse effect keeps us warm ? But, the enhanced greenhouse effect is responsible for global warming. Infrared radiation comes into the atmosphere and gets absorbed by the C=O, O-H and C-H bonds in H2O, CH4 and CO2. They vibrate gaining EK, which is dispersed, warming the Earth's surface. The greenhouse effect of a given gas is dependent on the: ? Concentration in the atmosphere (High CO2 etc) ? The ability to absorb infrared radiation (i.e. the bonding in it) The IPCC (bunch of chemists) collects evidence to force governments to stop producing so much CO2. Scientists should research ways in which global warming can be reduced ? Carbon-Capture and Storage (CCS)- This involves converting CO2 into liquid form. This liquid can be injected deep underground. ? Also reaction with metal oxides to form carbonates. (Magnesium Oxide) MO(s) + CO2(g) --> MCO3(s) ? The Kyoto Protocol was signed by developed nations governments to reduce output of greenhouse gasses to offset the progress of global warming. The scheme involved using carbon credits which can be traded around to penalise polluting nations. Some nations (Australia, USA (Obama)) are reluctant to join because of the impact on their economies.(See Geog notes) The ozone layer The Ozone Layer absorbs much of the harmful ultraviolet radiation emitted by

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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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Preperation of Antifebrin

Preparation of Antifebrin In this experiment, I am going to prepare the organic compound of antifebrin from readily available chemical reagents. Antifebrin is an odourless solid chemical of white flake-like appearance. Chemically, antifebrin is the amide phenylethanamide CH3ONHC6H5. It's slightly soluble in water. It does have the ability to self-ignite if it reaches the temperatures of 545°c but otherwise it's a stable compound. The pure crystals of antifebrin are plate shaped and white in colour. The antifebrin in this experiment is prepared from the reaction between phenylammonium chloride (C6H5NH3Cl) and ethanoic anhydride[ (CH3CO)2O ]. Chemical Equation for the Reaction: C6H5NH3+ Cl- + (CH3CO)2O CH3ONHC6H5 + CH3OOH + HCl Procedure & Observations: Procedure Observation Dissolve 1.0g of phenylammonium chloride in 30cm3 of water in a conical flask. Phenylammonium chloride is a greyish-green crystal like product. Adding water to it gives a solution pale grey with green tinge. After dissolving the solutions turns clear with a green-grey colour and no precipitate. Prepare a solution of 6.0g of sodium ethanoate in 25cm3 of water in a conical flask. Sodium ethanoate is a white powder. It dissolves completely in water to give a colourless solution. Carefully add 2cm3 of ethanoic anhydride to the solution of phenylammonium

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Production of Ethanol - Fermentation Vs Hydration

Production of Ethanol Fermentation Vs Hydration Ethanol, C2H5OH, is an alcohol produced industrially with many uses. Some of these include being used largely in the production of alcoholic beverages, cosmetics, antiseptics, drugs, inks, detergents and in solvents, and more over, it is very essential when mixed with petrol to make a bio-fuel, when made using renewable sources via fermentation. Ethanol can be produced by a number of ways, and in industry, it is made by the hydration of crude oil, or the fermentation of sugar. In the Hydration method, Crude oil, in this case - Ethene, as a natural gas - is essentially hydrated, meaning, water is added and Ethanol is the product of this reaction. Ethene, C2H4, is produced when crude oil is cracked, after being collected through the fractional distillation of fossil fuels that have been burnt. Water, H2O, is then reacted with the Ethene under a high temperature (approx 300oC) and a high pressure (60atm). Below is an equation of this reaction: CH2=CH2 (g) + H2O (g) › C2H5OH (l) As you can see, there is a double bond between the two molecules of CH2 in the Ethene. When Hydration occurs, the water added converts this double bond to Ethanol, which is the only product of this reaction. Fermentation, on the other hand, is the production of Ethanol by the use of plants. During this reaction, Carbohydrates from plants, mainly

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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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Comparing the enthalpy changes of combustion of different alcohols

Unit 1.4b Aim: Comparing the enthalpy changes of combustion of different alcohols Introduction: I am going to investigate the difference in enthalpy of combustion for a number of different alcohols. My aim is to find out the best fuel out of the five alcohols. I will calculate the value for enthalpy change by burning different fuels to heat a specific amount of water using the fact that 4.2J of energy are required to raise the temperature of 1g of water by 1°C. I will also produce a wide range of results and compare them to calculate their enthalpy change of combustion. Background information: The enthalpy change of combustion is the energy transferred to and from the surroundings at a constant pressure, when one mole of fuel burns completely. The symbol is ?H. The chemical reactions that release energy to their surroundings are called exothermic and the energy that transferred to them from the surroundings is called endothermic. ?H = ?H products - ?H reactants The units are kilojoules per mole (kJmol-1) Exothermic Ref: http://www.s-cool.co.uk/a-level/chemistry/chemical-energetics/revise-it/enthalpy-changes Exothermic reactions are more common. An example of exothermic reaction is: photosynthesis in plants where the energy comes from the sunlight. Energy cannot be destroyed but it can transfer from one form to another. The total energy of a system of reacting

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