Investigating Combustion Of Alcohols

Word Count: 2177 |


This investigation involves burning alcohol in the air. Key science-
Chemistry by Eileen Ramsden says that ” an alcohol is a series of
organic, homologous compounds, with the general formula Cn H2n+1OH”.
The alcohol reacts with the oxygen in the air to form the products
water and carbon dioxide:

Cn H2n+1OH +(n+n/2)-1O2 ? nH2O + nCO2

The structure of the molecules in this reaction is:

H H | | H – C – C – O- H + 3[O=O] ? 1/2[O=C=O] + 3[H-O-H] | | H H

This reaction is exothermic, as heat is given out. This is because the
amount reactant energy is more than the product energy the difference
between this is ?H, therefore some energy has been given out in the
form of heat.The energy is given out when forming the bonds between
the new water and carbon dioxide molecules. This can be shown in an
energy level diagram: Reaction co-ordinate ?H is the heat content,
which is the enthalpy, which is negative in exothermic reactions as
the diagram shows that energy is ‘lost’ as heat. Enthalpy is defined
as the energy of reaction, or the heat energy associated with a
chemical change. Chemical Principles By Master & Slowinski says that
“For any reaction carried out directly at a constant pressure, the
heat flow is exactly equal to the difference between enthalpy of
products and that of the reactants”, or: Qp = Hp – Hr = ?H Where Qp is
the heat flow at constant pressure, Hp is heat energy of products, and
Hr is the heat energy of the reactants.

To measure ?H given off, we must use this energy to heat something,
this will be water. This is assuming that all the heat produced by
combustion of fuel (?H) will equal the amount of heat absorbed by the
water (q). So I will measure the amount of energy required to do so.
This can be worked out by useing the formula: q = mass X specific heat
capacity X temperature rise 1000 Where q is the quantity of heat. The
specific heat capacity is the amount of energy required to heat the
substance, and is calculated using the formula q = MC?, where q is the
enthalpy, is the specific heat capacity and ? is the temperature rise.
I chose to use water as it is safe, easily obtainable, and has a
constant, reliable specific heat capacity of 4.2J/?C.

The bonds which are made in a exothermic reaction “are forces of
attraction between the atoms or ions in a substance” according to Key
science- Chemistry by Eileen Ramsden. These can be of two types:
covalent, in which the atoms share electrons. Examples of this are
water and carbon dioxide, which has a double covalent bond because it
shares two pairs of electrons are shared. The other type of bonds are
ionic, where a metal is involved. This is where electrons are
transferred from one ion to another, so there is an electrostatic
force between the ions.

The variables that must be controlled are:

* Mass of water

* Amount of wick on burner

* Type of alcohol

* Height of can above flame

* Type of can

* Time of burning

The alcohols used in this experiment will be from methanol, to
hexanol, their formulas and predicted enthalpy changes are:

Substance Formula – Predicted enthalpy change (KJ/mole)

Alcohol CnH2n+1OH

Methanol CH3OH -730

Ethanol C2H5OH -1370

Propanol C3H7OH -2010

Butanol C4H9OH -2670

Pentanol C5H11OH -3320

Hexanol C6H13OH 3980 N.B. The precicted enthalpy changes come form the
book of data by Nufield science. As the table shows, each alcohol
reaction increases each time by :

CH2 +11/2O 2 ? CO2 + H2O.

Investigating The Combustion Of Alcohols – Method

I did some preliminary results, the results of which are shown in the
table below:

Mass water (g) Initial temperature (C) Final temperature (C)
Temperature rise (C)

50 19 42 23

100 20 38 18

150 20 31 11

This experiment was done to see which mass of water would be best. The
50g mass was too large a rise as this caused too much heat to be lost
to the environment, and 150 was to small. Therefore the 100g value was
used, as this temperature was right for the enthalpy calculations.
Also the amount of wick was investigated, and I found that if it were
too large, there was more heat lost to the environment, and if it were
to small, most of the heat given out is lost in the can, so 6mm is the
optimum wick length. This will be kept constant throughout, as well as
the mass of water, and the temperature will be kept constant, to
ensure that only the type of alcohol is being investigated, so that
this can be a fair test.

As well as this, methods of reducing heat lost to the environment were
investigated. I found that by placing a hardboard draught excluder
around the experiment, and a cardboard lid with a hole for the
thermometer on top of the can, the heat lost was significantly reduced
to make this experiment more accurate. Stirring the water means that
there is uniform temperature in the can, and monitoring the
temperature rise to ensure uniform heating. The can is copper as
copper is a good conductor of heat, so more is transferred to the
water. The height of the can above the flame is also a factor, so this
needs too be kept constant just touching the can.

I decided to burn the alcohol for three minutes to make sure that
enough energy had been transferred for a accurate experiment. The can
was kept the same as different cans have different conduction
properties The heat is transferred from the flame by vibrating air
particles in the flame, caused by the exothermic reaction, which then
cause the molecules in the can to vibrate, and so the molecules in the
water vibrate.


* Measure out 100cm3 of water in to copper can using measuring

* Place can so flame just touches bottom of can

* Stir and record initial temperature of water

* Record initial mass of alcohol plus burner

* Start clock and light burner at the same time

* Stir water

* Burn for three minutes, then extinguish flame

* Record final temperature of water

* Record final mass of burner and alcohol

Investigating The Combustion Of Alcohols – Results

Initial temp (C) Max Temp (C) Temp rise (C) Initial burner (g) Finish
burner (g) No. C atoms

Methanol 1 17 37 20 48 47 1

Methanol 2 18 38 20 55 73 1

Ethanol 1 18 40 22 47 46 2

Ethanol 2 18 41 23 73 92 2

Propanol 1 19 39 20 43 44 3

Propanol 2 20 40 20 35 65 3

Butanol 1 20 42 22 44 43 4

Butanol 2 20 42 22 65 98 4

Hexanol 1 19 42 17 52 52 5

Hexanol 2 19 42 17 88 38 5

Pentanol 1 19 34 15 38 51 6

Pentanol 2 20 35 15 51 87 6 The controlled variables are the same can,
the 100g of water throughout, 6mm of wick, and the flame just touching
the can, to ensure this is a fair test, and that only the alcohol.

Investigating The Combustion Of Alcohols – Analysis

The graph shows two lines. The top line is the results predicted by
the chemistry data book- by Nufield Advanced Science. The lower line
is the line of best fit for the results that I obtained. The line is a
straight line that does not go through the origin. This is because
when y = 0, x = 1 carbon atom. The actual results graph is not
directly proportional, only proportional, as the graph was a straight
line. The predicted graph is directly proportional, as was predicted
it should be, this is shown as the number of carbon atoms is one, the
enthalpy change is -730, and when the number of carbon atoms doubles
to two, the enthalpy change nearly doubles to -1370, and when the
number of carbon atoms doubles again to 4, the enthalpy change, again
nearly doubles to -2670.

This is because earlier in the planning section, I predicted that the
number of carbon atoms would be proportional to the number the
enthalpy change. This is because when the number of carbon atoms
increases by 1, the reaction increases then number of molecules used
as follows: CH2 + 11/2O2 ? CO2 + H2O This shows that the number of
molecules increases by the same amount each time, and so should the
enthalpy change, if the all other variables were kept constant, and so
the predicted graph would look like this, showing that No. carbon
atoms ? enthalpy change. This is assuming that all the heat given off
by the burner is absorbed by the water: This graph is a straight line,
like my actual results, so my results support this part of the
prediction, but they are not directly proportional as predicted,
therefore my results do not support this part of the

Investigating The Combustion Of Alcohols – Evaluation

This experiment has many sources of error as the results were not what
were predicted. The real results, predicted results and % error, had
no ananomalous results.

My results are highly inaccurate as they are all nearly half the
predicted results. This is not due to the inaccuracy of not carrying
out the experiment properly as the error bars on the graph were too
small to be drawn accurately, as the two readings are almost the same.

These small inaccuracies are caused by slight differences in the
values of the fixed variables, like the mass of water not being
exactly 100g, due to incorrect reading of the measuring cylinder
caused by a paralax error, caused when the scale is read at an angle
to the eye, as the light is reflacted through the glass, causing the
reading to appear somewhere else . The same error could have been
meant an error in the reading of the thermometer, causing there to be
wrong temperature readings. The amount of wick on the burner will not
have been exactly the same (6mm) on each burner as this was difficult
to measure. This would have caused differences in the amount of
alcohol burnt. The flame was not always just touching the can, as this
again was difficult to measure accurately, and would have caused
differences in the amount of heat given off as the temperature of the
flame is different and different heights. The can might not have been
the same as this experiment was done over two lessons, and different
cans have different conduction properties. Also the time for each burn
might not have been three minutes exactly each time as it takes time
for the final reading to be read and the flame to be extinguished
after the time is up. The thermometer was not in the same place at
each temperature recording, as even though the water was stirred,
there would be differences in the temperature of the water at
different depths.

To make the results slightly more accurate, I would use more accurate,
maybe electronic ways of measuring temperature and volume, also
measure the wick length and height of can above the flame. I would
also have marked the can used, so that it could be used again, and had
a more accurate timing system As these errors were only small, they
could not have made the massive differences between the predicted
results, so there must have been other factors that caused the heat
from the burner not to reach the water, and cause these errors.

The whole experiment was surrounded in mats to stop a draught taking
heat from the flame, however there were still gaps at the tops of the
experiment where a draught could have caused heat to be lost. Also the
can, although copper, would not have transferred all the heat across,
some would be lost heating up the can. The can being copper meant that
as well as heat being added easily, heat is lost just as easily, as
the water heats up. There was a card board lid to prevent some of this
heat lost, but the sides of the can were not insulated, so huge
amounts of heat were given of by the can. The clamp, which is metal,
and was touching the can will have meant some of the heat was
transferred into the clamp and stand, causing more heat loss form the
experiment. In order for this experiment to be more accurate, I would
have to insulate the can and the clamps, completely exclude all
draughts use a better conductor other than water to heat, and use a
thinner can, made of a better heat conducting material.

Given that the range of the experiment was only 6 alcohols from
methanol to hexanol and that the experiment was only 3 minutes, and
the inaccuracies of the experiment, I would say that the evidence is
not strong enough to draw firm conclusions from. If this experiment
was to be done again, then all the possible sources of error mentioned
would have to be counteracted and controlled, as well as using a much
wider range of readings of many more alcohols, burn them for different
periods of time, heat different substances other that water,
investigate the other variables. I would also take many more readings
so a that a much more accurate average could be taken. Other
experiments could have been done investigating other organic
compounds, such as hydrocarbons, to see if they behave similarly, and
investigate them under different conditions, such as at extremes of
temperature and pressure.

You May Also Find These Documents Helpful

Allegory Of American Pie By Don Mc Lean

Ask anyone what was the defining moment in the rock history of the 1960s was and all you will get is a one word answer: Woodstock. The three day rock festival that defined an era was only one of many music festivals of the '60s. But Woodstock has come to symbolize, "an era of peaceful, free- loving, drug- taking hippie youth, carefree before harsher realities hit..." (Layman 40). The Woodstock festival ended a century filled with many metamorphoses of rock'n'roll, from the era of pop music to the rebirth of folk music to the invention of acid rock. But some cynics say that rock'n'roll died with the death of Buddy Holly before the 60s even began. One such person is Don McLean. The poet behind the haunting epic song about the death of 'danceable' music, McLean wrote the ever popular song, "American Pie" (appendix 1). The most important song in rock'n'roll history, "American Pie", is the song about the demise of rock'n'roll after Buddy Holly's death and the heathenism of rock that resulted. Although McLean himself won't reveal any symbolism in his songs, "American Pie" is one of the most analyzed pieces of literature in modern society. Although not all of its secrets have been revealed, many "scholars" of the sixties will agree that the mystery of this song is one of the reasons it has become so successful- everyone wants to know the meanings of its allegories. Proof of "American Pie's" truth lies in the allegory of the song. Many People enjoy the song but have no idea what it means- Who is the Jester? What is the levee? When the deeper story is found, the importance of the song is unearthed. "American Pie" is not only a song, it is an epic poem about the course of rock'n'roll...

Carl Orffs Philosophies In Music Education

While Carl Orff is a very seminal composer of the 20th century, his greatest success and influence has been in the field of Music Education. Born on July 10th in Munich, Germany in 1895, Orff refused to speak about his past almost as if he were ashamed of it. What we do know, however, is that Orff came from a Bavarian family who was very active in the German military. His father's regiment band would often play through some of the young Orff's first attempts at composing. Although Orff was adamant about the secrecy of his past, Moser's Musik Lexicon says that he studied in the Munich Academy of Music until 1914. Orff then served in the military in the first world war. After the war, he held various positions in the Mannheim and Darmstadt opera houses then returned home to Munich to further study music. In 1925, and for the rest of his life, Orff was the head of a department and co-founder of the Guenther School for gymnastics, music, and dance in Munich where he worked with musical beginners. This is where he developed his Music Education theories. In 1937, Orff's Carmina Burana premiered in Frankfurt, Germany. Needless to say, it was a great success. With the success of Carmina Burana, Orff orphaned all of his previous works except for Catulli Carmina and the En trata which were rewritten to be acceptable by Orff. One of Orff's most admired composers was Monteverdi. In fact, much of Orff's work was based on ancient material. Orff said: I am often asked why I nearly always select old material, fairy tales and legends for my stage works. I do not look upon them as old, but rather as valid material. The time element disappears, and only the spiritual power remains. My...

Johann Sebastian Bach Biography

Throughout the history of music, many great composers, theorists, and instrumentalists have left indelible marks and influences that people today look back on to admire and aspire to. No exception to this idiom is Johann Sebastian Bach, whose impact on music was unforgettable to say the least. People today look back to his writings and works to both learn and admire. He truly can be considered a music history great. Bach, who came from a family of over 53 musicians, was nothing short of a virtuosic instrumentalist as well as a masterful composer. Born in Eisenach, Germany, on March 21, 1685, he was the son of a masterful violinist, Johann Ambrosius Bach, who taught his son the basic skills for string playing. Along with this string playing, Bach began to play the organ which is the instrument he would later on be noted for in history. His instruction on the organ came from the player at Eisenach's most important church. He instructed the young boy rather rigorously until his skills surpassed anyone?s expectations for someone of such a young age. Bach suffered early trauma when his parents died in 1695. He went to go live with his older brother, Johann Christoph, who also was a professional organist at Ohrdruf. He continued his younger brother's education on that instrument, as well as introducing him to the harpsichord. The rigorous training on these instruments combined with Bach?s masterful skill paid off for him at an early age. After several years of studying with his older brother, he received a scholarship to study in Luneberg, Germany, which is located on the northern tip of the country. As a result, he left his brother?s tutelage and went to go and study there. The teenage years brought Bach to several parts of Germany where he...


Michelangelo was pessimistic in his poetry and an optimist in his artwork. Michelangelo?s artwork consisted of paintings and sculptures that showed humanity in it?s natural state. Michelangelo?s poetry was pessimistic in his response to Strazzi even though he was complementing him. Michelangelo?s sculpture brought out his optimism. Michelangelo was optimistic in completing The Tomb of Pope Julius II and persevered through it?s many revisions trying to complete his vision. Sculpture was Michelangelo?s main goal and the love of his life. Since his art portrayed both optimism and pessimism, Michelangelo was in touch with his positive and negative sides, showing that he had a great and stable personality. Michelangelo?s artwork consisted of paintings and sculptures that showed humanity in it?s natural state. Michelangelo Buonarroti was called to Rome in 1505 by Pope Julius II to create for him a monumental tomb. We have no clear sense of what the tomb was to look like, since over the years it went through at least five conceptual revisions. The tomb was to have three levels; the bottom level was to have sculpted figures representing Victory and bond slaves. The second level was to have statues of Moses and Saint Paul as well as symbolic figures of the active and contemplative life- representative of the human striving for, and reception of, knowledge. The third level, it is assumed, was to have an effigy of the deceased pope. The tomb of Pope Julius II was never finished. What was finished of the tomb represents a twenty-year span of frustrating delays and revised schemes. Michelangelo had hardly begun work on the pope?s tomb when Julius commanded him to fresco the ceiling of the Sistine Chapel to complete the work done in the previous century under Sixtus IV. The overall organization consists of four large triangles at...

Oscar Wilde

Oscar Fingal O'Flahertie Wills Wilde was born in Dublin Ireland on October 16, 1854. He is one of the most talented and most controversial writers of his time. He was well known for his wit, flamboyance, and creative genius and with his little dramatic training showing his natural talent for stage and theatre. He is termed a martyr by some and may be the first true self-publicist and was known for his style of dress and odd behavior. Wilde, 1882 His Father, William Wilde, was a highly accredited doctor and his mother, Jane Francesca Elgee, was a writer of revolutionary poems. Oscar had a brother William Charles Kingsbury along with his father's three illegitimate children, Henry, Emily, and Mary. His sister, Isola Emily Francesca died in 1867 at only ten years of age from a sudden fever, greatly affecting Oscar and his family. He kept a lock of her hair in an envelope and later wrote the poem 'Requiescat' in her memory. Oscar and his brother William both attended the Protora Royal School at Enniskillen. He had little in common with the other children. He disliked games and took more interest in flowers and sunsets. He was extremely passionate about anything that had to do with ancient Greece and with Classics. Wilde during school years In 1871, he was awarded a Royal School Scholarship to Trinity College in Dublin and received many awards and earned the highest honor the college offered to an undergraduate, the Foundation Scholarship. In 1874, he also won the College's Berkley Gold Medal for Greek and was awarded a Demyship to Magdalen College, Oxford. After graduating from Oxford, Oscar moved to London with his friend Frank Miles, a well-known portrait painter of the time. In 1878 his poem Ravenna was published, for which he won the...

The History Of Greek Theater

Theater and drama in Ancient Greece took form in about 5th century BCE, with the Sopocles, the great writer of tragedy. In his plays and those of the same genre, heroes and the ideals of life were depicted and glorified. It was believed that man should live for honor and fame, his action was courageous and glorious and his life would climax in a great and noble death. Originally, the hero's recognition was created by selfish behaviors and little thought of service to others. As the Greeks grew toward city-states and colonization, it became the destiny and ambition of the hero to gain honor by serving his city. The second major characteristic of the early Greek world was the supernatural. The two worlds were not separate, as the gods lived in the same world as the men, and they interfered in the men's lives as they chose to. It was the gods who sent suffering and evil to men. In the plays of Sophocles, the gods brought about the hero's downfall because of a tragic flaw in the character of the hero. In Greek tragedy, suffering brought knowledge of worldly matters and of the individual. Aristotle attempted to explain how an audience could observe tragic events and still have a pleasurable experience. Aristotle, by searching the works of writers of Greek tragedy, Aeschulus, Euripides and Sophocles (whose Oedipus Rex he considered the finest of all Greek tragedies), arrived at his definition of tragedy. This explanation has a profound influence for more than twenty centuries on those writing tragedies, most significantly Shakespeare. Aristotle's analysis of tragedy began with a description of the effect such a work had on the audience as a "catharsis" or purging of the emotions. He decided that catharsis was the purging of two specific emotions, pity and...

Scholarship Essay About Goals

Ever since I was a young kid I have always been interested with aircraft. I was so curious of how airplane's fly. I remember taking my toys apart to see how it works. As a kid I wanted to go to the airport to watch the airplanes land and fly and pondered how this happens. Other kids wanted to go to the amusement places. As I grew older I became more and more interested in aircraft and the technology behind it. I always involved myself with aviation early on. I read books and magazines on aviation, took museum tours, built model airplanes. When I was younger my father would take me to aircraft repair facilities where I would watch in great fascination. In my teens, went up to the military bases and befriended many soldiers involved with aircraft and asked them numerous questions. I got to meet many aeronautics engineers and borrowed their old textbooks and read them till the wee hours of the morning. As technology improved with information superhighway, I logged on the web. Stayed up for hours and hours searching through web pages and web pages of information about aircraft and technology. I started my elementary school in the Philippines, then we moved to U.S. and continued my high school education and graduated. Enrolled at the CCSF to pursue my college education and now I am in the 2nd year in CCSF taking aeronautics. My goal now is to obtain my AS degree from the City College of San Francisco (CCSF) so I can transfer to a University and get a Bachelors degree and to continue for my Masters degree in Aeronautics Engineering. I will strive hard to reach the peak level of my career which is a Professor and hopefully to be an aeronautic professor so...

Circus Circus Enterprises Case Studies

Executive Summary: Circus Circus Enterprises is a leader and will continue to be in the gaming industry. In recent years, they have seen a decline in profit and revenue; management tends to blame the decrease on continuing disruptions from remodeling, expansion, and increased competition. Consequently, Circus has reported decreases in its net income for 1997 and 1998 and management believes this trend will continue as competition heightens. Currently the company is involved in several joint ventures, its brand of casino entertainment has traditionally catered to the low rollers and family vacationers through its theme park. Circus should continue to expand its existing operations into new market segments. This shift will allow them to attract the up scale gambler. Overview Circus Circus Enterprises, Inc founded in 1974 is in the business of entertainment, with its core strength in casino gambling. The company?s asset base, operating cash flow, profit margin, multiple markets and customers, rank it as one of the gaming industry leaders. Partners William G. Bennett an aggressive cost cutter and William N. Pennington purchased Circus Circus in 1974 as a small and unprofitable casino. It went public in 1983, from 1993 to 1997; the average return on capital invested was 16.5%. Circus Circus operates several properties in Las Vegas, Reno, Laughlin, and one in Mississippi, as well as 50% ownership in three other casinos and a theme park. On January 31,1998 Circus reported net income of 89.9 million and revenues of 1.35 billion, this is a down from 100 million on 1.3 billion in 1997. Management sees this decline in revenue due to the rapid and extensive expansion and the increased competition that Circus is facing. Well established in the casino gaming industry the corporation has its focus in the entertainment business and has particularly a popular theme resort concept....

Effect Of Civil War On American Economy

The Economies of the North and South, 1861-1865 In 1861, a great war in American history began. It was a civil war between the north and south that was by no means civil. This war would have great repercussions upon the economy of this country and the states within it. The American Civil War began with secession, creating a divided union of sorts, and sparked an incredibly cataclysmic four years. Although the actual war began with secession, this was not the only driving force. The economy of the Southern states, the Confederacy, greatly if not entirely depended on the institution of slavery. The Confederacy was heavily reliant on agriculture, and they used the profits made from the sale of such raw materials to purchase finished goods to use and enjoy. Their major export was cotton, which thrived on the warm river deltas and could easily be shipped to major ocean ports from towns on the Mississippi and numerous river cities. Slavery was a key part of this, as slaves were the ones who harvested and planted the cotton. Being such an enormous unpaid work force, the profits made were extraordinarily high and the price for the unfinished goods drastically low in comparison; especially since he invention of the cotton gin in 1793 which made the work all that much easier and quicker. In contrast, the economical structure of the Northern states, the Union, was vastly dependent on industry. Slavery did not exist in most of the Union, as there was no demand for it due to the type of industrial development taking place. As the Union had a paid work force, the profits made were lower and the cost of the finished manufactured item higher. In turn, the Union used the profits and purchased raw materials to use. This cycle...

Evaluation Of The Effectiveness Of Trade Embargoes

Although I am a strong critic of the use and effectiveness of economic sanctions, such as trade embargoes, for the sake of this assignment, I will present both their theoretical advantages and their disadvantages based upon my research. Trade embargoes and blockades have traditionally been used to entice nations to alter their behavior or to punish them for certain behavior. The intentions behind these policies are generally noble, at least on the surface. However, these policies can have side effects. For example, FDR's blockade of raw materials against the Japanese in Manchuria in the 1930s arguably led to the bombing of Pearl Harbor, which resulted in U.S. involvement in World War II. The decades-long embargo against Cuba not only did not lead to the topple of the communist regime there, but may have strengthened Castro's hold on the island and has created animosity toward the United States in Latin America and much suffering by the people of Cuba. Various studies have concluded that embargoes and other economic sanctions generally have not been effective from a utilitarian or policy perspective, yet these policies continue. Evaluation of the effectiveness of Trade Embargoes Strengths Trade embargoes and other sanctions can give the sender government the appearance of taking strong measures in response to a given situation without resorting to violence. Sanctions can be imposed in conjunction with other measures to achieve conflict prevention and mitigation goals. Sanctions may be ineffective: goals may be too elusive, the means too gentle, or cooperation from other countries insufficient. It is usually difficult to determine whether embargoes were an effective deterrent against future misdeeds: embargoes may contribute to a successful outcome, but can rarely achieve ambitious objectives alone. Some regimes are highly resistant to external pressures to reform. At the same time, trade sanctions may narrow the...