The Pros And Cons Of Combustion Of Alcohols

An Investigation into the Enthalpies of the Combustion of Alcohols = == == == ==

could be the reason? The experiment was conducted at 6600ft. Water tends to boil at a lower temperature at higher altitudes.

The air pressure fell below the vapor pressure, and the water boiled. 10) Use your observations to compare the atmospheric pressure outside the beaker to the air pressure inside the beaker before lighting the candle. The pressure is equal before lighting the candle because the beaker took the air from outside the beaker, and nothing has been done to change the

Table 1 summarises the results from the primary data collected. Figure 5 indicates there is a linear relationship between the molecular weight and heats of combustion. Figure 6 compares the heats of combustion of the primary data, the accepted values and values calculated from the bond dissociation energy. Figure 6 compares the heat of combustion values identified by the bond dissociation energy calculations, the accepted values and experimental values when 80g of water is heated by 10°C. The bond dissociation energies do not take into account the hydrogen bonding and the accurate energy required to change the tested alkanol from an aqueous state to a gaseous state. The experiments done to identify the accepted values were conducted

The random errors experienced in this experiment impacted the results gathered from experiment a lot less than the systematic errors. 1. Flame was not concentrated on the same point of the beaker. While conducting the experiment, there were small draughts through out the lab, which caused the movement and change of position of the heat energy of the flame.

In this science unit we had to keep 200 milliliters of boiling water hot as warm as possible for 20 minutes. For trial one we put tin foil all around flask so the heat waves would reflect back to the flask. Also we put tin foil on the top of the flask to stop convection because warm rises. So when the hot air rises we wanted the tin foil to reflect the hot air back into the flask. Then we were going to put the flask in in a wooden box with a small volume, but then keegan forgot to bring in the box so we had to put the flask with the tin foil around it in our ELA project.Then we put a ton of cotton balls all around the flask and tin foil to insulate the water in the flask. At the end of trial 1 we lost 15.7℃. One thing we did well is we kept the heat in by insulating with cotton balls. Another thing we did well was stopping convection by putting tin foil on the top.

50mL of 2M NaOH was added to the two stacked Styrofoam cups in a 400mL beaker. The cup was then covered with a plastic lid and a temperature probe was inserted through the lid and into cup in a way so that it did not touch the bottom. 3-4 temperature readings were then collected by clicking “collect” on LabQuest to start Run 2, and initial temperature was determined. 50mL of 2M NH4Cl was then added to the NaOH solution in the cup and swirled around. The rest was repeated from the first

The father reported that the reason for the evaluation is because the parents are unable to come to an agreement regarding custody of Sofia.

have five C-H bonds, one C-C bond, one C-O bond and one O-H bond. To

We suspended the flask at a slight angle, up to its neck in the water bath, making certain that the water never touched the foil cap. To suspend a thermometer in the water we rolled a piece of napkin paper, and used a clamp to supported to the apparatus, making certain that the thermometer bulb didn’t touch the bottom of the beaker. We turned on the heating plate, and boiled the water in the water bath. We waited for the whole unknown liquid to vaporize, and recorded the water-bath temperature. As soon as the liquid completely vaporized, we removed the clamp-flask assembly from the water bath.

The heat absorbed or released from a system under constant pressure is known as enthalpy.(Khan Academy)This is because as the number of Carbon atoms increase. The chain of hydrocarbons will also be added to thus making it longer. As we move down the homologous group, the chain grows longer in size this is due to the additional CH3 Molecules added onto every next Alcohol within the group. Thus resulting in more energy being required to break apart the longer newly formed molecule. When reactions between any alcohol and an oxygen in the air they create C02 and H2O.(University of Texas)

The energy that comes from the combustion from either ethanol or petrol comes from burning these hydrocarbons in order for the oxygen from the air to combine and combust (See Ethanol and the Environment for more). Energy is produced when the hydrocarbon bonds between the carbon and the hydrogen and

The aim of this experiment was to test the heat of combustion over a period of time, and the energy required to combust alcohols with different carbon chain levels. It was hypothesised that the higher the carbon chain of the alcohol present, the faster the heat of combustion will occur. Meaning more energy will be released for a higher carbon chain. After calculating the results from the experiment it was found that the hypothesis was partially supported. The reasoning for this is as the alcohol that posses a higher carbon chain, generally increased there reaction rates. However there were a few exceptions to this rule.

This experiment is focused on heat of combustion using hydrocarbons as fuel. All three fuels produce combustion reactions which are exothermic. When bonds are formed or broken the most common form of energy released or taken in is heat energy. Heat of combustion is a way of measuring how much energy is output from a combustion reaction, the energy that is output is usually in the form of heat.

Diesel fuel is a mixture of alkane hydrocarbons (a compound containing hydrogen and carbon). These hydrocarbons are saturated, essentially meaning the fuel has a low density – this is important so that the vehicle using such fuel can operate efficiently (Energy Information Administration, 2013). Furthermore, alkanes are extremely combustible, ensuring sufficient burning of the diesel (Nave, R.). After observing these characteristics of diesel, it became essential to prove that alcohols too had properties similar to these (despite sources supporting the change from diesel to a combination of diesel and alcohol). Alcohols do have equivalent hydrocarbons (Chemical Industry, 2015). The alcohol molecule too contains oxygen contributing greatly to the act of combustion (Natural Resources and Environment Department). This property, together with its saturated nature