Enthalpy - investigate the difference in enthalpy of combustion for a number of alcohols
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 of 20oc in the water, I
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 oxygenunder the stated conditions'.
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, by using a calculation that it takes 4.2J of energy to heat 1g of water by 1 c I plan to compare the enthalpy changes of combustion of different alcohol´s. As I know that combusting different substances produces differing amounts of energy, I plan to find out which alcohol, out of methanol, ethanol, propanol and butanol, produces the most energy when burned in air. I will do this by heating 100ml of water by 50?C and using the calculation of it takes 4.2j of energy to heat 1g of
To work out the enthalpy change of combustion of alcohols
Enthalpy of combustion planning Aim: To work out the enthalpy change of combustion of alcohols To work out the enthalpy change of combustion of the alcohols, the energy output must be measured. This simplest way of doing this accurately is to use the thermal energy of combustion to raise the temperature of a substance with a known specific heat capacity. The rise in temperature of this substance can then used to work out the thermal energy used to do this work. Basic plan Apparatus Metal calorimeter Thermometer measures to 0.1 oc Clamp stand Alcohol with spirit burner Heat proof mat Scales that measure to two decimal places Wooden splint 00cm3 measuring cylinder that measures 1cm3 For safety To begin with prepare a table remove all items of stationary from the surface and place them in bags, leaving only the paper and pen that are to be used to record the results. Remove bags from under the desks and place them in the designated positions. With the exception of the scales collect all the apparatus above, and place them on the prepared table. To ensure the weights recorded on the scales are reliable. Switch the scales on, wait until the balance has settled, once the balance has settled press the tare button to ensure that the balance reads 0.00 and the balance registers the entire weight of the spirit burner alcohol. Weigh the alcohol in the burner to two
Finding the Concentration of Limewater in a Titration Using Hydrochloric Acid as a reagent
Finding the Concentration of Limewater in a Titration Using Hydrochloric Acid as a reagent Aim: The aim of this experiment is it to find the concentration of Limewater (g dm-3) in a titration experiment using hydrochloric acid of concentration exactly 2.00 mol dm-3 as a reagent. Equipment: I will need a burette, 25ml pipette, pipette filler, white tile, teat pipette, clamp stand, boss head, clamp, limewater, phenolphthalein indicator, hydrochloric acid, volumetric flask, funnel, distilled water, conical flasks, safety gear and a calculator. Equation: 2HCl (aq) + Ca(OH)2 (aq) --> 2H20(l) + CaCl2(aq) Quantity and concentration of reagent used: 100ml & 2.00 mol dm-3 HCL Method: First things first, Lab coats and Goggles must be worn at all times. This safety rule should not be disobeyed due to fact we are using hazardous chemicals their hazards must be taken into account. The chemicals that we will use are limewater, hydrochloric acid and Phenolphthalein indicator. The hazards are as follows: Hydrochloric acid - Very corrosive, irritant. Limewater (alkali) - Irritant. Phenolphthalein Indicator - May cause irritation of the respiratory and digestive tract if ingested. Can also cause CANCER. Now, to perform the titration the first thing that needs to be done is to dilute the HCL to a suitable concentration. To do this you will need the pipette and the pipette filler
Potassium permangonate
An Investigation into the Kinetics of the reaction between Potassium Permanganate and Oxalic Acid with a Sulphuric Acid Catalyst Aim The primary objective of my investigation is determining the orders of reaction for the oxidation of oxalic acid by potassium permanganate, with a sulphuric acid catalyst: 2 MnO4-(aq ) + 5 H2C2O4(aq ) + 6 H3O+(aq ) --> 2Mn2+(aq ) + 10 CO2(aq ) + 14 H2O I will find this by applying alterations to certain factors that affect the rate of the reaction, and observing which ones have a greater bearing. These factors will be the concentrations of each reactant and the catalyst, and also the temperature of the solutions at the time of reaction. I will consider: o What is the rate equation? o What is the order of reaction for each reactant? o What is the activation enthalpy of the reaction? Apparatus * 250 cm³ volumetric flasks * Bulb pipettes-10cm³, 25cm³, 50cm ¯³ * Teat pipettes * 100 cm³ beakers * Distilled water * Digital Thermometer * Water Bath * Colorimeter * Stopclock * Cuvettes Apparatus Descriptions and Justifications The 250 cm³ volumetric flasks have been designed to allow the preparation of solutions, with a very high degree of accuracy regarding both volume and concentration. I will be using class B flasks, which have a tiny error. These volumetric flasks have been calibrated at room temperature, so will be
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
Experiment. The aim of this experiment is to identify which substances are present in the flu medicine powder
Experiment A1: Qualitative Tests on Organic compounds The aim of this experiment is to identify which substances are present in the unknown white powder. This includes the compound that are said to be present and the substances that are typically found in a flu powder. The results from this test are as follows: Test for substance Observations Explanation Phenylephrine Hydrochloride test with Cu2+ +CuSO4: the solution turned into a light blue colour. +NaOH: the solution turned dark blue +Ether: the solution split into two layers; clear and dark blue at the bottom. From the observation made it is visible that unknown white powder did test positive for Phenylephrine. Up until the addition of NaOH the outcomes of the two test were similar. Despite there being a yellow precipitate at the bottom the unknown white powder does contain Phenylephrine. Unknown tested for Phenylephrine +CuSO4: solution was cloudy to begin with. Changed colour from cloudy light green to yellow. +NaOH: solution turned dark green with yellow precipitate. +Ether: Formed three layers; clear, blue and yellow precipitate at the bottom. Ascorbic Acid test with Ag+ + Nitric Acid: solution turned from a white cloudy colour to yellow cloudy. + Silver Nitrate: solution turned into a dark creamy colour with silver precipitate. The purpose of testing Phenylephrine in this way is to see
Extraction of alcohol from beer by distillation.
Dr. Sharma Chemistry Unit 22 EXTRACTION OF ALCOHOL FROM BEER AIM The objective of this practical is to extract alcohol (pure) from (Tennenent’s Super Strong Lager) beer. APPARATUS & CHEMICALS . Thermometer 2. Measuring Cylinder 3. Spatula 4. Anti-bumping Granules 5. Boiler (Round Bottom Flask) 6. Fractional Distillation Flask 7. Matches 8. Flameless Heater 9. Condenser 0. Bucket With Ice 1. Moveable Platform 2. Watchglass 3. Pipette 4. Tennenent’s Super Strong Lager (Beer) METHOD & OBSERVATIONS . Health & Safety precautions were taken; this includes wearing lab coats and goggles in order to avoid harm to one’s body or surroundings. 2. The apparatus was set up to carry out the experiment. 3. A spatula was used to insert anti-bumping granules into the boiler (these help the distribution of heat throughout the solvent). 4. 250cm3 of beer was measured and poured into the boiler by a funnel. 5. The boiler was placed into the flameless heater, which was switched on. 6. After some time, the beer began to boil, and vapours began to rise. The vapours pass through the fractional distillation column and into the condenser, where it cools down and turns back into the state of liquid. 7. The liquid pours down into the round bottom flask inside a bucket with ice, to maintain its liquid state. 8. The thermometer was constantly observed, this is because
The aim of this experiment was to recrystallise an impure sample of benzoic acid from hot water, and determine its purity through infra-red spectroscopy.
Experiment 4-Purification by recrystalisation. AIM The aim of this experiment was to recrystallise an impure sample of benzoic acid from hot water, and determine its purity through infra-red spectroscopy. The melting point was also measured using the melting point apparatus. Method: . First, approximately 1.5g of impure benzoic acid was weighed out using a four decimal point mass balance and the weight was recorded. 2. Next, 50cm3 of water was measured out using a 50cm3 measuring cylinder and water was added to a 100ml beaker and heated using a Bunsen burner. 3. Once the water was boiling the Bunsen burner was removed. The impure sample of benzoic acid was added and stirred using a glass rod. The solution was left to cool. After the beaker was cool enough to hold in the hand, it was placed in an ice bath for approximately 5 minutes. 4. The solution was passed through a Buchner funnel and flask after cooling so all impurities were removed and a frothy clear solution was produced and white crystals remained on top of the filter paper. 5. The beaker was then washed out with water several times and the remains were poured into the Buchner funnel. The glass rod was also rinsed and the remains were also transferred into the Buchner funnel. The crystals were then washed with cold water and left to dry for approximately 5 minutes. 6. A clean watch glass was then weighed
Classifications of Alcohols Experiment
Objective: . To differentiate different types of alcohol. Introduction: In organic chemistry, alcohols from the functional group of hydroxyl groups are organic compounds which are characterized by one or more hydroxyl (−OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain). Alcohols have the general formula CnH2n+1OH (where n represent the number of carbon atom in the compound) or R-OH (where R represent an alkyl group). Alcohols is usually classified into three classes, the primary alcohols (1°), secondary alcohols (2°) and tertiary alcohols (3°).Alcohols fall into different classes depending on how the -OH group is positioned on the chain of carbon atoms. In a primary (1°) alcohol, the carbon which carries the -OH group is only attached to one alkyl group. In a secondary (2°) alcohol, the carbon with the -OH group attached is joined directly to two alkyl groups. In a tertiary (3°) alcohol, the carbon atom holding the -OH group is attached directly to three alkyl groups. The attached alkyl groups may be from the combination of same or different groups. R = alkyl group The boiling points of the normal alcohols increase regularly with the increase of the molecular weights. The primary alcohols boil at a higher temperature than the secondary alcohols that are isomeric with them. Similarly, the latter have higher boiling points than their
