Combustion of Alcohols Summative Practical Report
GREEN boxes are the checklist for each section detailing what is required, individual squares can
be checked by clicking them.
Guiding information should be deleted once you finish your report. Leave only your responses with
the section titles for your final report.
In-text referencing must be used throughout
REPORT TITLE Replace with an informative title.
[Place your name here]
INTRODUCTION
BACKGROUND INFORMATION
Define the term carbon cycle and explain the main steps in the cycle. (you may include a diagram)
The carbon cycle is the process in which carbon moves through the Earth’s atmosphere. It is
important as it helps regulate the climate by controlling the levels of greenhouse gasses in
the atmosphere. The carbon cycle can be seen below in Figure 1.
Figure 1: Diagram of the carbon cycle from Farm Carbon Toolkit
Define the terms ‘carbon sink’ and ‘carbon source’ and give examples of each.
A carbon sink is a natural or artificial reservoir that absorbs and stores carbon, thus reducing
the carbon dioxide in the atmosphere. Some examples are forests and oceans as both trees
and water absorb carbon dioxide. A carbon source, however, is the opposite as it is
something that releases more carbon than it absorbs. Some examples are volcanic eruptions
and breathing as both release more carbon than they absorb.
Explain what combustion reactions are and their role in the carbon cycle. Give an example word
equation for a combustion reaction.
Combustion reactions are a chemical process in which a substance reacts with oxygen to
create light and heat.
Briefly describe how combustion is being investigate in this experiment.
Include an explanation for how each of the alcohols tested are different to each other.
In this experiment, combustion is being investigated by seeing how much mass each
alcohol loses and what their change in temperature was. The alcohols lost from 1.3g to
0.16g and had a change in temperature from 5 degrees to 1.3 degrees.
Concepts have been described in detail
All relevant concepts have been included
Word equation included with correct conventions
How the experiment is investigating combustion has been explained
Information is referenced
AIM
The aim of this investigation is to investigate how the number of carbon atoms in an alcohol affects the
energy released.
HYPOTHESIS
State the hypothesis (predicted outcome) of the experiment
It is predicted that the more mass an alcohol loses, the higher the change in temperature will be.
Prediction is logical based on science
Prediction includes independent and dependent variable
VARIABLES
State the variables for the practical
independent – factor changed by the experimenter
dependent – factor measured to determine effect of independent variable
control – factor kept the same in every test to ensure a fair experiment
The independent variable for this experiment was the alcohols as 5 different ones were tested. The
dependent variables that were measured were how much mass the alcohols lost and what their change in
temperature was. The control variables were the time the alcohol was heated for, the number of times the
alcohol was tested, and the equipment used throughout the experiment.
Independent variable
Dependent variable
Control variables control 1:
(give specific amounts and control 2:
units for chemicals and control 3:
equipment)
Variables are specific and detailed
Units are provided for IV and DV
Only one variable given for IV and DV
At least 3 correct control variables have been given
MATERIALS & METHOD
list all the equipment you used for your experiment in dot point form. You can take this from the task
sheet, but if you did not use everything/ used additional material, make sure your equipment list
reflects this.
In this investigation we used alcohol, an 100ml beaker, a thermometer, a heatproof mat, a
tripod, an electronic scale, and some matches. The method for this investigation was as
follows: first, we set up the heatproof mat, the alcohol, a tripod, and the beaker. We then put
50ml in the beaker, lit the chosen alcohol, and placed the thermometer in the beaker. We
then waited one minute and recorded the highest temperature on the thermometer. We then
put out the alcohol and measured to see how much mass it lost. We then did this with all
four other alcohols.
Create a diagram of the experimental set up. Every piece of equipment does not need to be included.
Can be hand-drawn or use chemix.org
All labels included
Shows different variations of the IV tested
Important equipment for recording data has been included
Diagrams are clear to see and understand
RESULTS
In this space, place in the following results:
Table 1: results showing the raw data for each alcohol.
Change in Energy Change in Energy released
ALCOHOL
Temp (°C) released (J) Mass (g) per gram (J/g)
785.71
ethanol 5 1045 1.33
1-propanol 1.33 277.97 1.67 166.45
1-butanol 3.33 695.97 0.63 1104.71
1-pentanol 3.67 767.03 0.8 958.79
1-hexanol 4.33 904.97 0.83 1090.33
Table 2: results for average energy released
ALCOHOL Energy released measured (J)
ethanol 1045
1-propanol 277.97
1-butanol 695.97
1-pentanol 767.03
1-hexanol 904.97
Table 3: Percentage (%) error calculations
Energy Expected true
ALCOHOL released value for energy % error
measured (J) released (J)
ethanol 1045 39,501 -97.35
1-propanol 277.97 56,112 -99.51
1-butanol 695.97 22,743 -96.94
1-pentanol 767.03 30,240 -97.46
1-hexanol 904.97 32,370 -97.21
Each table and graph must include a descriptive label i.e. figure 1 – scatterplot showing how the average
duration of exercise affects the heart rate of a test subject
DISCUSSION
General trends and comparison
Use the average data to address the following:
Discuss how the energy released per gram changed as the number of carbon atoms increased. Be
detailed in your response.
Discuss any unusual results observed in the data, and give a possible explanation for why/how they
occurred.
State whether the hypothesis supported and explain why.
The hypothesis was/ was not supported.. since …
State whether the aim was achieved or not and explain why.
The aim of the practical was / was not achieved as…
Place your responses from the questions above here in full sentence form.
Data has been described in detail, mentioning the numerical values for the different alcohols tested
Unusual results have been discussed and possible explanation given
Stated whether the aim was achieved or not with evidence
Stated whether the hypothesis was supported or not with evidence
Precision
Discuss the range of the data for the trials of each different alcohol.
(calculate the range for each alcohol)
range = highest value – lowest value
Extension: Discuss how scattered the values are around the trendline of the scatterplot.
State whether the precision was low, medium or high.
place answers here
Range of the data for each pH solution has been discussed
Precision level has been stated based on evidence
Accuracy
Discuss the %error values for the different alcohols tested.
Discuss whether the %error values are large or small.
State whether the accuracy was low, medium or high.
place answers here
size of %error values have been discussed for each alcohol
Accuracy level has been stated based on evidence
Validity
Explain whether there were any control variables that were not kept consistent and if they had a
low, medium, or high impact on the data
State the level of precision and accuracy of the data and use this (plus the above part) to state the
level of validity (low, medium, high)
place answers here
How controlled variables would have impacted data has been described in detail
Validity level has been determined by taking into account controlled variables, precision level and accuracy
level
Evaluation of method
Random errors
Describe 1 random error that could have occurred in your practical (error that affects each
measurement differently)
Explain how the error would have affected the results recorded (be specific and detailed)
One random error that could have occurred is…
Describe another example of a random error that could have occurred in your practical
Explain how the error would have affected the results recorded (be specific and detailed)
Another random error that could have occurred is…
Systematic errors
Describe one example of a systematic error that could have occurred (error related to the equipment
used)
Explain how the error would have affected the results recorded (be specific and detailed)
One systematic error that could have occurred is…
Describe another example of a systematic error that could have occurred
Explain how the error would have affected the results recorded (be specific and detailed)
Another systematic error that could have occurred is…
At least 3 potential errors have been given (at least 1 random and 1 systematic)
Errors given are relevant for the practical
Each error has been described clearly
Each error has been correctly described as random or systematic
A detailed description of how the error would have impacted the results obtained has been given and is
specific
No improvement suggestions have been given
CONCLUSION
The aim of this experiment was [restate aim]. The aim of this experiment [was/was not] achieved
because [in one or two sentences, restate what was found regarding the aim].The hypothesis of
this experiment was that [restate hypothesis]. The hypothesis of this experiment was [supported/
negated]. This was evident, as [link one or two major results that supports your answer]. However,
major errors that impacted this data include [state the major errors that may have impacted
results] which had a [describe effect on quality of data obtained and overall level of validity].
Bibliography (In Harvard style)
All science information has been referenced within the text
Equations have been written with the correct conventions throughout
Bibliography is given in alphabetical order by author’s last name
Each reference listed has been referred to within the practical report
Minimal spelling and grammar errors throughout the practical
Scientific language has been used throughout the report
No personal pronouns have been used (e.g. me, our, my, I think.etc)
The sections of the report have been given in the correct order
