Enthalpy Changes of Combustion of Different Alcohols Aim: The aim of this experiment is to find out how the enthalpy change (total energy released when the alcohols are completely combusted in a plentiful supply of air) for 5 different alcohols is affected by the number of carbon atoms in the alcohol and other factors contributing to the molecular structure. Prediction: I predict that as the amount of carbon atoms in the alcohol increases, the higher the enthalpy of combustion will
Analysis and Results of Enthalpy Change ALCOHOL AVERAGE MASS BURNT (G) METHANOL 1.54 ETHANOL 1.02 PROPAN-1-OL 0.77 BUTAN-1-OL 0.69 PENTAN-1-OL 0.55 HEXAN-1-OL 0.52 Following the gathering of results, the enthalpy change of combustion of the alcohols was calculated using the equation from page 2: Energy Transferred = Mass of water x Temperature rise x specific heat capacity (4.17) Now to calculate the enthalpy change of combustion, the following
The Enthalpy Change of Different Alcohols My aim is to compare the enthalpy change of combustion of different alcohols in relation to the structure of each molecule. The enthalpy change of combustion of a fuel is a measure of the energy transferred when one mole of the fuel burns completely. In a chemical reaction, bonds must either be made or broken, this involves an enthalpy change. The formation of bonds is exothermic, energy is lost to the surrounding; on the other hand, breaking bonds
Use of Enthalpy Changes of Metal Reactions The problem: The problem that I will investigate is how to use enthalpy changes of metal reactions to experimentally test the reactivity series of common metals. Therefore the area that I am looking at is reactions involving metals and the heat energy that is evolved when these take place. In brief the reactivity series of metals is a list in which metals are ranked according to their reactivity, from the most reactive metals (such as Pottassium)
Determining the Enthalpy Change of A Reaction If Calcium Carbonate, CaCO3, is heated it decomposes into Calcium Oxide, CaO and Carbon Dioxide, CO2. [IMAGE]CaCO3 CaO + CO2 The aim of this experiment is to determine the enthalpy change of this reaction. To do this I will react both Calcium Carbonate and Calcium Oxide, separately, with 2mol dm-3 Hydrochloric Acid, HCl. By recording the temperature changes in each reaction, and using Hess's Cycle, I will be able to work out the enthalpy change
Comparing the enthalpy changes of combustion of different alcohols What are alcohols? ================== Alcohol is the common family name for the hydrocarbon group alkanols. At least one of the hydrogen groups is replaced by an OH group. They are all organic compounds. The general formulas for the alcohols are: CnH(2n+1)OH Where n represents a number. The first and simplest member of the alkanols family is methanol. Its molecular formula is CH3OH. You can now see that each member of the
The change in enthalpy for the combustion of magnesium metal Abstract ======== Hess’s law of heat summation states that the value of DH for a reaction is the same whether it occurs directly or as a series of steps. This principle was used to determine the change in enthalpy for a highly exothermic reaction, the combustion of magnesium metal. Enthalpy changes for the reactions of Mg in HCl (aq) and MgO (s) in HCl (aq) were determined experimentally, then added to that for the combustion of hydrogen
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. 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) CaCl2(aq) + CO2(g) + H2O(l) GRAPH ¼ in
Comparing the Enthalpy Changes of Combustion of Different Alcohols Aim: I will find the enthalpy change of combustion of a number of alcohols so that I can investigate how and why enthalpy change is affected by molecular structure of the alcohol. Outline: I will use Methanol, Ethanol, Propanol and Butanol in the experiment. I will use these four because they should give me clear results, and they range from short chained to long-chained hydrocarbons, so patterns should be easy to
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
Investigating the Enthalpy Change of Combustion for Various Alcohols P l a n n i n g Aim: To investigate the enthalpy change of combustion for various alcohols Alcohols will be burnt to heat up water. The aim is to find out how much energy is produced when burning the following alcohols : ethanol, propanol and butanol. Alcohols react with oxygen in the air to form carbon dioxide, water and energy is liberated (exothermic reaction), because the reactants' energy is higher than that of
Comparing the Enthalpy Changes of Combustion of Different Alcohols Aim Combustion of alcohols is exothermic; energy is given out. Salter's Chemical storylines says, " Different fuels have different enthalpy changes". I will investigate how the carbon chain length of the alcohol affects its enthalpy of combustion. Preliminary Work ---------------- Chemistry for you page 184 says, "breaking bonds requires energy, it is endothermic ". It also says " making new bonds gives out energy
Comparing The Enthalpy Change Of Combustion Of Different Alcohols The aim of my experiment is to investigate the enthalpy of combustion of a range of alcohols. The standard enthalpy of combustion is the enthalpy change that occurs when 1 mole of a fuel is burned completely in oxygen under standard conditions – 1 atmosphere pressure and 298K. All combustion reactions are exothermic which is why I am expecting all the values for the enthalpy change of combustion to always be negative. Prediction
Comparing the Enthalpy Changes of Combustion of Different Alcohols Introduction In this investigation I will set out to find the differences in the enthalpies of combustion of 6 different alcohols. These are methanol, ethanol, butan-2-ol, propan-1-ol, propan-2-ol and 2Methylpropan-1-ol. I can then find the variation between straight chain and branched molecules and isomers. Planning -------- Method ------ Carrying Out The Experiment To carry out the experiment, I will fill
Investigation into the Factors that Affect the Enthalpy Change During a Displacement Reaction The Task -------- To investigate the factors affecting the enthalpy change during a displacement reaction. Background Knowledge ==================== In this investigation a displacement reaction will be observed. A displacement reaction occurs when more reactive metal displaces, (or removes) a less reactive metal from a solution of its salt. Also known as chemical bullying because
Chemistry Aim- To determine the enthalpy change for the reaction of between cooper sulphate and zinc. Materials Required- Calorimeter Glass Thermometer Weighing Machine Digital Stop Watch Measuring Cylinder Cuso4 . 5H2o Zinc Metal Powder Distilled Water By adding the access amount of zinc in the constant amount of aqueous cooper sulphate and measuring the change in temperature over time, the chande in enthalpy of the reaction can be determined using calorimeter calculation. Materials
BLACK Melting Point (0C) - 220 - 101 - 7 113 Boiling Point (0C) - 188 - 35 59 183 ELECTRON AFFINITY Electron affinity is the enthalpy change when gaseous atoms of an element gain electrons to become negative ions. The FIRST ELECTRON AFFINITY of an element is the ENTHALPY CHANGE WHEN ONE MOLE OF GASEOUS ATOMS GAINS ELECTRONS TO FORM ONE MOLE OF GASEOUS IONS. Electron affinity DECREASES as you DESCEND the group VII: F à 333kJ Cl à 346kJ of
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
This lab has a typical percentage error usually around 30%-40%. By looking at the percentage error of the calculated enthalpy and entropy, the percentage error is large but small when compared to the typical percentage error that is usually found in the lab. This typically large percentage error shows that there is an error in this lab that causes the experimental data to be less than the theoretical data. In this lab there were many opportunities that an error could have occurred and skewed the
Calculating the Enthalpy change during Combustion: The formula for the Enthalpy change during combustion is ∆H = mc∆T Where ∆H is the enthalpy change during combustion measured in joules, m is the mass of the water in grams, c is the specific heat capacity of water the ∆T is the change in the temperature in kelvin. Therefore, Enthalpy change during combustion= 100g x 4.18 J g-1 K-1 x 40K = 16720 J 6. Calculating the Enthalpy change of Combustion: The Enthalpy change of Combustion of