IDENTIFICATION OF AN ORGANIC UNKNOWN
IDENTIFICATION OF AN ORGANIC UNKNOWN When doing each procedure, take extra care and wear eye protection, gloves, and lab coat because there's a high risk due to the organic chemical been unknown. Risk assessment before the test alkene and phenol: Procedure / Chemical Risk Precaution Information derived from Bromine water Toxic: very toxic by inhalation. Irritant: irritant to skins and eyes Harmful: by inhalation, contact with skin or swallowed. If swallowed, wash out mouth and drink a glass or two of water. Seek medical attention as soon as possible. If inhaled, remove victim and put where there's fresh air. If chemical gets into eyes, wash off with plenty of water and seek medical help. Wear eye protection and gloves during handling. Dispose using fume cupboard. Cleapss card page number 15 Unknown organic compound Explosive: risk of explosion by shock, friction, fire, or other source of ignition. Toxic: by inhalation or if swallowed. And it's very toxic to skin. Skin stain yellow on contact with which may be followed by dermatitis. If swallowed, wash out mouth and drink a glass or two of water. Seek medical attention as soon as possible. If inhaled, remove victim and put where there's fresh air. If chemical gets into eyes, wash off with plenty of water and seek medical help. Wear eye protection, and wear gloves during handling of chemical. If chemical
Finding Out how much Acid there is in a Solution
Finding out How Much Acid there is in a Solution When a metal is extracted from its ore, a waste product is often sulphur dioxide (SO2). This is then converted into sulphuric acid (H2SO4) and sold. To sell sulphuric acid, its accurate concentration must be known. In this investigation, I will use a titration method to attempt to find the accurate concentration of a sample of sulphuric acid thought to have a concentration of between 0.05 and 0.15 mol dm-3. The chemicals which I will use to do this will be solid anhydrous sodium carbonate (Na2Co3) and an indicator. Finding out How Much Acid there is in a Solution - Plan Quantities of Chemicals Required In this investigation, the chemical reaction used will be the neutralisation reaction between sulphuric acid and sodium carbonate: H2SO4 (aq) + Na2CO3 (aq) --> Na2SO4 (aq) + CO2 (g) + H2O (l) As the sodium carbonate has to be aqueous for this reaction, I will need to make up a solution of sodium carbonate before I begin the titration. I will need to choose an appropriate concentration for this solution and an appropriate volume of it to make up. As there is a 1:1 ratio between the moles of sulphuric acid and sodium sulphate used in this reaction, I should make up a solution of sodium carbonate of similar solution to that of the sulphuric acid. Assuming that the concentration of the sulphuric acid is around 0.1 mol dm-3, this
Investigating the enthalpy change of different fuels when combusted.
Investigating the enthalpy change of different fuels when combusted. Aim: The aim of this experiment is to see how the enthalpy changes vary when different alcohols are combusted in standard conditions. The alcohols used will be: Ethanol, Propan-1-ol, Butan-1-ol, Pentan-1-ol and Hexan-1-ol. These alcohols all have the OH functional group on the first Carbon atom of the molecule. Background Knowledge The enthalpy change of combustion (also shown as ?Hc) is a measure of energy when one mole of a fuel burns completely in air, at a standard temperature and pressure. This standard temperature is 298 Kelvin and 1ATM pressure. Maintaining these conditions would be complicated; therefore the experiment will be carried out in normal conditions. Any drastic alterations to these conditions will need to be taken care of to maintain a degree of accuracy. As combustion is exothermic (heat is transferred to the environment) all of the enthalpy changes will be negative. The formula for enthalpy change is: Energy Transferred= Heat capacity of water x Change in water temp x mass of water. Or E=MC?T Hess's Law. "the enthalpy change for any chemical reaction is independent of the intermediate stages, provided the initial and final conditions are the saeme for each route." This basically means that in an enthalpy cycle, detours can be made to reach the final products and the total
Comparing the enthalpy changes of combustion of different alcohols
Oliver White - Comparing the enthalpy changes of combustion of different alcohols. Theory When chemical reactions occur, bonds between atoms are broken and new bonds are made. The amount of energy needed to break a particular bond is called its bond enthalpy(H). We cannot measure the enthalpy of a substance but we can measure the change in enthalpy(?H) when a reaction occurs. ?H = Hproducts - Hreactants Hproducts is the final enthalpy of the system, measured in joules. In a chemical reaction, Hproducts is the enthalpy of the products. Hreactants is the initial enthalpy of the system, measured in joules. In a chemical reaction, Hreactants is the enthalpy of the reactants. Enthalpy change in a chemical reaction gives the gives the quantity of energy transferred to or from the surroundings, when the reaction is carried out openly. In an exothermic reaction, the enthalpy of the reacting system decreases. ?H is negative. In an endothermic reaction, the enthalpy of the reacting systems increases. ?H is positive. When chemists talk about enthalpy changes they often refer to the system meaning the reactants and the products of the reaction they are interested in. The system can lose or gain enthalpy depending on the surroundings meaning the rest of the world: the test tube, the air etc. I will be investigating the enthalpy change of combustion of different alcohols. The
The Preparation of 1-bromobutane
The Preparation of 1-bromobutane The aim of this assignment is to produce 1-bromobutane in the laboratory and write a report on the preparation. To do this, I will need to follow the following steps: - Carry out the reaction by reflux - Separate the 1-bromobutane from the reaction mixture - Purify the 1-bromobutane - Test for it's purity Background Information ---------------------- One way of preparing 1-bromobutane is to start with btan-1-ol and replace the -OH group on it with a - Br group by means of a substitution reaction. The reaction can be represented by the equation: CH3CH2CH2CHOHHBr â†' CH3CH2CH2CH2Br + H2O This is a nucleophilic substitution reaction, which comes about by the reaction between butan-1-ol and Br- ions. The reaction is done in the presence of a strong acid and the first step involves bonding between H+ ions and the O atom on the alcohol: This gives the C atom to which the O is attached a partial negative charge. It is now more readily attached by Br- ions forming Bromobutane. The overall equation for the reaction is: CH3CH2CH2OH +Â(r) Br-CH3CH2CH2CH2Br + H2O. Structural Isomers Isomers are molecules that have the same molecular formula but have a different arrangement of the atoms in space. That excludes any different arrangements, which are simply due to the molecule rotating as a whole or
I am going to investigate the difference in enthalpy of combustion for a number of alcohols, the enthalpy of combustion being the 'enthalpy change when one mole of any substance is completely burnt in oxygen under the stated conditions'.
Enthalpy By Iram 6L Enthalpy I am going to investigate the difference in enthalpy of combustion for a number of alcohols, the enthalpy of combustion being the 'enthalpy change when one mole of any substance is completely burnt in oxygen under the stated conditions'. I will be attempting to find how the number of carbon atoms the alcohol contains effects the enthalpy change that occurs during the combustion of the alcohol. Method I plan to measure the enthalpy change by burning the alcohol, using a spirit burner, I will then use the heat produced during the combustion of the alcohol to heat 100ml of water that will be situated in a copper calorimeter directly above the burning alcohol. The calorimeter is made of copper as copper has a high thermal conduction value, this basically means that it is a good conductor of heat so a lot of the heat the copper receives will be passed on to the water which I am then able to measure. During the experiment I will be taking a number of measurements, I will firstly take the initial temperature of the water and initial mass of the alcohol I will then burn the alcohol until an increase in temperature of 20oc has occurred in the water I will then reweigh the alcohol. The measurements * Mass of alcohol burned (g) * Temperature increase (oc) will tell me what mass of alcohol is used during combustion to cause the temperature increase
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
Antacid Lab. Are name brand antacids better than generic brand antacids to neutralize stomach acids that may cause diseases? Which antacid is more effective? Are both brands equally effective?
The Effective Antacid Generic or Brand Name? SNC2DO Mr. Nestor User 3/25/2009 Question Are "name brand" antacids better than generic brand antacids to neutralize stomach acids that may cause diseases? Which antacid is more effective? Are both brands equally effective? Introduction The customary acid that is originated in a healthy stomach is also known as gastric acid. Gastric acid is one of the main emitting of the stomach, together with several enzymes and intrinsic factor. Chemically it is an acid solution with a pH of 1 to 2 in the stomach lumen, consisting mainly of hydrochloric acid (HCl), and large quantities of potassium chloride (KCl) and sodium chloride (NaCl). Stomach acidity is a frequent problem. The stomach produces acid to digest food that we consume. As we eat, the cells that border the stomach pump acid liquefy the food. However, the conflict occurs when these cells compose large amount of acid unnecessary for the stomach. The result of too much acidity is the feeling of a burning sensation or acid regurgitation. One of the most popular ways to prevent stomach acidity is by taking antacids that can be brought over-the-counter. Antacids are any material, usually base or base salt, used to neutralize stomach acids. The antacids execute a neutralization reaction. The antacids perform tasks such as, they buffer gastric acid, elevating the pH to decrease
Atom Coursework
Atom Coursework The atom is the smallest unit of an element that retains the chemical properties of that element. An atom has an electron cloud consisting of negatively charged electrons surrounding a dense nucleus. The nucleus contains positively charged protons and electrically neutral neutrons. When the number of protons in the nucleus equals the number of electrons, the atom is electrically neutral; otherwise it is an ion and has a net positive or negative charge. An atom is classified according to its number of protons and neutrons: the number of protons determines the chemical element and the number of neutrons determines the isotope of that element. Relative to everyday experience, atoms are minuscule objects with proportionately tiny masses. Atoms can only be observed individually using special instruments such as the scanning tunneling microscope. Over 99.9% of an atom's mass is concentrated in the nucleus with protons and neutrons having roughly equal mass. Each element has at least one isotope with unstable nuclei that can undergo radioactive decay. This can result in a transmutation that changes the number of protons or neutrons in a nucleus. Electrons possess a set of stable energy levels, or orbital, and can undergo transitions between them by absorbing or emitting photons that match the energy differences between the levels. The electrons determine the
Experiment to Compare the Enthalpy Changes of Combustion of Different Alcohols
Experiment to Compare the Enthalpy Changes of Combustion of Different Alcohols Introduction: This plan will try to outline how the experiment of comparing changes of combustion of different alcohols will be conducted and what results are expected. Background When chemical reactions take place they are often accompanied by energy changes. Chemical reactions most frequently occur in open vessels. That is, they take place at constant pressure. Enthalpy refers to energy at constant pressure (volume may vary). Enthalpy: An example is best to illustrate to show enthalpy works. Methane - how much energy does its molecules contain? The first thing needed is the amount of methane present = 1 mole (16 g). What ever its value, the total amount of energy in a given amount of a substance (sometimes called the Heat energy content) is known as the enthalpy, denoted H. Methane is a fuel to get energy from it, react it with oxygen. CH4(g) + 2O2(g) ? CO2(g) + 2H2O(l) The above chemical equation shows that 2 moles (64 g) of oxygen molecules are required to burn 1 mole of methane. Again, it is impossible to know the total enthalpy (heat energy content) of the oxygen. Likewise, we can't know the total heat energy content of 1 mole of CO2 and 2 moles of H2O (the products). Enthalpy Change ?H = (HCO2 + 2HH2O) - (HCH4 + 2HO2) In general, ?H = ?Hproducts - ?Hreactants But
