Investigating Factors Affecting the Heat of Combustion of Alcohols
PLANNING SECTION
Introduction
------------
Alcohols are organic substances, and consist of Hydrogen, Oxygen and
Carbon. All alcohols are toxic but the amount that can be tolerated by
the human body varies for different alcohols. For example drinking
small amounts of Methanol can lead to blindness and even death.
Ethanol is the only alcohol that can be drunk safely and is found in
all alcoholic drinks. Throughout this investigation I am going to
investigate to different factors that affect the breakdown of an
alcohol.
[IMAGE]e.g. Methane (HCO) + Oxygen (O2) Carbon dioxide (CO2) + Water
(H2O)
Aim
---
I am going to investigate increasing the chain length and see what
effect there is on the heat of combustion.
Preliminary Work
----------------
The point of preliminary work is to find out what things that I should
vary and keep constant. For my preliminary work I used computer
software called Focus Science Investigation 2. This software enables
you to simulate experiments. This means that I am able to quickly
carry out experiments to help in planning for my investigation.
----------------------------------------------------------------------
Alcohol
Temperature Increase (oC)
Mass of burner before exp. (g)
Mass of burner after
exp. (g)
Change in mass (g)
Methanol
20
170.00
167.08
2.92
Ethanol
20
170.00
167.77
2.23
Propan-1-ol
20
170.00
168.03
1.97
Butan-1-ol
20
170.00
168.16
1.84
Pentan-1-ol
20
170.00
168.24
1.76
Having found these results I then worked out the combustion per mole
of alcohol.
Alcohol
Mass of water heated (g)
Heat evolved during reaction (J)
Change in mass of burner
(g)
Combustion of one mole of alcohol (kJ/mole)
For the sample calculations, let’s use the marshmallow as an example. Its initial mass was 0.66 grams and its final mass was 0.36 grams. To calculate the amount burned, subtract 0.36 from 0.66 to get 0.30 grams. (Mass burned = mi- mf). To find the marshmallow’s change in temperature, use the formula (ΔT =
Input variables In this experiment there are two main factors that can affect the rate of the reaction. These key factors can change the rate of the reaction by either increasing it or decreasing it. These were considered and controlled so that they did not disrupt the success of the experiment. Temperature-
Next, we measured 1.07 g of magnesium oxide, using a balance in the fume hood, added it to the HCl in the calorimeter, and shut the lid quickly to conserve heat. This mixture was “swirled” and allowed a few moments to react. The final temperature was recorded and DT determined. GRAPH GRAPH
In the span of only a few pages, L.B. Church has given us an overview of the winemaking process. He has done so with sufficient detail for those in the chemistry community to follow along, yet still in a cursory enough manner as to not bog them down with the unnecessary. Written as if it were the procedure of an experiment, he has given enough information for the experiment to be repeated, tested, validated and improved upon. And that is almost assuredly his goal from the very beginning, as it must be for any published author in the chemistry community.
In the case, “Facing a Fire” prepared by Ann Buchholtz, there are several problems and issues to identify in determining if Herman Singer should rebuild the factory due to a fire or retire on his insurance proceeds. I believe that this case is about social reform and self-interest. I think that Singer needs to ask himself, what is in the firm’s best economic interests. There are several things to question within this case, what should Herman Singer do and why, should he rebuild the factory or begin retirement, if he rebuilds, should he relocate the firm to an area where wages are lower and what provisions, if any, should Singer make for his employees as well as for the community?
This container must have a value of specific heat capacity so I can calculate heat transferred to it as well. Probably the most conductive container available for use in the classroom is a calorimeter. As well as not wasting energy on the heating of the container, I could also try to stop heat from escaping the top and edges of the container by covering it with a fitting lid. I will try to prevent the wind from blowing the flames in a different direction so all the windows must be shut. HYPOTHESIS More energy is released as more bonds are formed, below is the list of approximate energy required to break and form all bonds involved in burning alcohols.
To gain reliable results we needed a temperature rise of 50 degrees centigrade in the quickest time. possible. Then we can do it. Using the Propanol burner with different volumes of water we. tested the flame at varying distances under the calorimeter measured.
Investigation of the heat energy produced by combustion of various alcohols. Aim: ---- To investigate how different alcohols produce different amounts of heat energy through combustion. I will be heating water using different alcohols as fuels and measuring the amount of fuel consumed.
one gram of water by 1ºC. I chose to use water because it is safe,
cm∆T where c is the specific heating capacity of water (4.17 Jg-1K-1) -m is the mass of water, in g -∆T is the change of temperature of the water Apparatus Apparatus I will use Size of the apparatus Value /quantity distill water / >3 litres, as much as possible* thermometer 0-110C thermometer 1 measuring cylinder 100 cm3 1 electronic balance correct to 2 decimal places 1 Bunsen burner / 1 draught shielding each approx. 20cm x 20cm 5 metal calorimeter *** 4 clamp about 1 meter 6 spirit burner with wick / 4 match/wooden stick / as many as possible burner cap / 4 tile as big as possible 1 Propan-1-ol / half filled the spirit burner * Butan-1-ol / half filled the spirit burner * Butan-2-ol / half filled the spirit burne * Cyclohexanol / half filled the spirit burner * ***-I will find out in preliminary test *-Half filled the spirit burner because alcohol should be away from
Alcohol is an ethanol containing substance that is a common beverage in many social and private settings. Alcohol is also a teratogen, therefore alcohol co...
The data of all three unknown solutions resulted in measurements that were all off by at least 7% of the theoretical percentages. For example, the 1st unknown solution was supposed to consist of about 30% Ethanol and around 70% N-Propanol, though the actual data we received put Ethanol at 20% and N-Propanol at around 80%. This 10% margin of error could have been caused by a multitude of mistakes including the liquid evaporating before it was injected, cross-contamination, bubbles within the needle, and students not clicking the button simultaneously as they injected the alcohol. Our teacher warned us about how quickly the alcohols evaporated from the needle and told us to keep our hands at the back of the syringe to prevent as much evaporation
reaction is the rate of loss of a reactant or the rate of formation of
Pyrolysis is a rapid thermal decomposition process of organic biomass, in absence or little supply of oxygen, brought about by high temperatures into useful biofuel products such as pyrolysis oil, ethanol, biodiesel, methanol etc. During the process, large hydrocarbon molecule’s chemical composition structure breaks down into relatively smaller molecules into solid (char), liquid or gas phase (Figure 1). The process is very similar to many other biomass decomposition processes such as torrefaction, carbonization, devolatilization etc. however pyrolysis cannot be compared to gasification due to external activation required for gasification.
Alcohol is a class of organic compounds that is characterized by the presence of one or more hydroxyl groups (-OH) attached to a carbon atom. Alcohol was unknowingly produced centuries ago when fermentation occurred to crushed grapes (Pines, 1931). In today’s society alcohol is produced for the use of household products such as varnishes, cleaning products, but is more commercially important in the liquor business. A chemical process called fermentation accomplishes the production of ethanol, the alcohol or liquor. From there, the ethanol goes through distinct processes to become the dark and clear liquors on the store shelves.