The document describes an experiment to determine the molar heat of combustion of ethanol and isopropyl alcohol. Raw data is presented from trials measuring the temperature change of water over time during the combustion of each alcohol. The temperature change is used to calculate the heat absorbed by the water and the molar combustion heat of each alcohol. Calculations are shown determining the mass and volume of alcohol used, and accounting for uncertainties in measurements. The goal is to compare the bond strength and molar combustion heat of the two alcohols.

1. Koz 1
INTERNATIONAL BACCALAUREATE
CHEMISTRY LAB REPORT
COMBUSTION ENTHALPYH
--
Candidate: Serra Koz
Supervisor: --
May 2014

2. Koz 2
INTRODUCTION
Combustion analysis employs a chemical reaction, a process in which one or more substances
are converted into one or more different ones. Compounds form and change through chemical
reactions. Water can be made by the reaction of hydrogen with oxygen. A combustion
reaction is a particular type of chemical reaction in which substance combines with oxygen to
form one or more oxygen containing compounds. Combustion reactions also emit heat. The
heat produced in a number of combustion reaction is critical to supplying our society’s energy
needs. (Tro, 2011, pg. 110)
In a chemical reaction energy is required to break bonds in the reactants, and energy is given
out when new bonds are formed in the products. The most important type of energy in
chemistry is heat. If the bonds in the products are stronger than the bonds in the reactants then
the reaction said to be exothermic, as heat is given exothermic process include combustion
and neutralization. In endothermic reaction heat is out to the surroundings. Examples of
absorbed from the surroundings because the bonds in the reactants are stronger than the bonds
in the products. It is important to be able to distinguish between heat and temperature as the
terms are often used loosely. Heat is a measure of the total energy in a given amount of
substance and therefore depends on the amount of substance present. Temperature is a
measure of the ‘hotness’ of a substance. It represents the average kinetic energy of the
substance, but is independent of the amount of substance present. (Neuss, 2007, pg. 92)
Isopropyl is a type of alcohol with the molecular formula of
C3H8OH or C3H8O as shown in the Figure 1 and has a
physical properties is colorless, flammable liquid compound.
The molecular weight of isopropyl is 60.095 g mol-1
~60.10 g
mol-1
and density of isopropyl alcohol is 786.00 g cm-3
.
Figure 1

3. Koz 3
Ethanol (Ethyl alcohol) is another type of alcohol with the molecular formula of C2H6O as
shown in the Figure 2 and has physical properties of colorless liquid and flammable chemical
compound. The molecular weight of ethanol is 46.06844 g mol-1
~46.07 g mol-1
and density of
ethyl alcohol is 789.00 g cm-3
. The molar combustion heat of the ethanol is 1360 kJ mol-1
.
Figure 2
AIM: The aim of this experiment is determine the molar heat of combustion of isopropyl and
ethanol and compare the bond strength of alcohols.
RESEARCH QUESTION: How does strength of a bond effect the molar heat of combustion
(enthalpy) of alcohols according to the room temperature, initial volume of water (200 mL),
initial volume of the alcohols (100 mL), time duration for the reaction (10 min.) and distance
between the wick and beaker?
HYPOTHESIS: If the strength of a bond increases, the molar combustion heat given out by an
alcohol increases.

4. Koz 4
Table 1: Dependent, Independent and Controlled Variables
Independent
Variables
Types of
Alcohols/Ethanol and
Isopropyl
The type of alcohol changed during the experiment
and observed the combustion heat of alcohols.
Dependent
Variables
Temperature of the
Water/ °C
The temperature of the water changed during the
experiment and measured by the thermometer.
Volume of Water/mL
(200 mL)
Volume of water was same during the experiment
and measured by the graduated cylinder. If the
volume of water change, then the temperature rate
can be changed as well.
Initial Volume of the
Alcohols/mL
(100 mL)
The initial volume of the each type of alcohols was
same during the experiment and measured by the
graduated cylinder. Initial volume of alcohol affects
the heat combustion during the experiment.
Controlled
Variables
Room Temperature/
°C (25°C)
Room temperature measured by thermometer and it
was constant during the experiment.
Time of the Reaction/s
The measuring time was same during the
experiment. The temperature rate measured in the 1st
,
2nd
, 3rd
, 4th
, 5th
, 6th
, 7th
, 8th
, 9th
and 10th
minutes by the
aid of the chronometer. If the range of the time is
changed, then temperature of the reaction is changed.
Distance between
Wick and Beaker/cm
(5 cm)
The distance between wick and beaker was same
during the experiment. It measured by ruler. If the
distance between wick and beaker changed, the
temperature difference of the reaction changed as
well.

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MATERIALS
 400 mL Beaker (±5) (x2)
 Oil Lamps (x2)
 50 mL Graduated Cylinder (±0.5) (x2)
 200 mL Pure Water
 100 mL Ethyl Alcohol (Ethanol)
 100 mL Isopropyl Alcohol
 Lighter
 Thermometer (±0.1) (x2)
 Scale (±0.01)
 Chronometer (±0.005)
 Ruler (±0.5)
 Tripod Stand (x2)
 Dropper (±0.25) (x2)
 Small Funnel (x2)
PROCEDURE
i. 200 mL pure water was added in the each beaker.
ii. 100 mL ethanol and 100 mL isopropyl was measured and ethanol and isopropyl
alcohol was added in oil lamps.
iii. The masses of wicks before using was measured and recorded.
iv. On the top of the oil lamps, the pure water was placed in beakers with the aid of tripod
and the initial temperature of the pure water was measured.
v. The wick was ignited as shown in the Figure 4 and the temperatures was measured at
1st
, 2nd
, 3rd
, 4th
, 5th
, 6th
, 7th
, 8th
, 9th
and 10th
minutes and the data were recorded.
vi. Final volume of alcohols was measured.
vii. Final masses of wicks were measured. (After the reaction, wicks absorb alcohols)
viii. Experiment was repeated for 3 more times.
Figure 3
Figure 4

6. Koz 6
PRESENTATION OF DATA METHOD
Raw data (Table 2, Table 3, Table 4, Table 5 and Table 6) include 3 of the trials and
uncertainty of the thermometer (±0.1), graduated cylinder (±0.5), scale (±0.01) and
chronometer (±0.005). According to the raw data table, take the avarage of the trials and make
a processing data table. Sketch best fit line graph according to the processing data.
DATA COLLECTION & PROCESSING
Quantitative Data:
Table 2: Temperature Change of Pure Water for Combustion of Ethanol
Time/ s Temperature/ °C (±0.1)
(±0.005 s) Trial 1 Trial 2 Trial 3
Average
Temp.
0 21.0 17.0 18.2 18.7
60 25.0 23.6 21.9 23.5
120 29.8 29.7 25.2 28.2
180 31.3 30.9 29.0 30.4
240 35.0 33.0 32.8 33.6
300 37.5 35.4 35.1 36.0
360 38.9 37.5 38.4 38.3
420 42.2 40.7 41.0 41.3
480 44.7 43.0 44.2 43.9
540 47.0 45.1 46.9 46.3
600 49.5 47.0 50.0 48.8
Table 2 shows the temperature change of pure water during the combustion of ethanol.

7. Koz 7
Calculation 1: Take the average of the 0th
second;
21.0 + 17.0 + 18.2
3
= 18.7
Take the average of the all values as shown in the example below.
Table 3: Temperature Change of Pure Water for Combustion of Isopropyl Alcohol
Time/ s Temperature/ °C (±0.1)
( ±0.005s) Trial 1 Trial 2 Trial 3
Average
Temp.
0 19.0 17.0 18.7 18.2
60 21.5 20.8 21.0 21.1
120 23.0 25.0 23.5 23.8
180 25.0 27.0 26.0 27.0
240 26.5 30.2 28.6 28.3
300 29.0 32.0 30.5 30.5
360 31.0 34.2 33.5 32.9
420 33.9 35.7 35.0 34.8
480 36.3 37.7 37.0 37.0
540 38.5 39.5 39.2 39.1
600 40.0 41.0 41.4 40.8
Table 3 shows the temperature of water (ΔT) during the combustion of isopropyl alcohol.
Calculation 2: Take the average of the all values.

8. Koz 8
Table 4: Change of Volume of Ethanol
Table 4 shows the differences between initial and final volume of ethanol. (Note: The amount
of ethanol that is absorbed by wick does not consist.)
Table 5: Change of Volume of Isopropyl
Table 5 shows the differences between initial and final of isopropyl alcohol. Note: The
amount of isopropyl alcohol that is absorbed by wick does not consist.)
Volume/mL (±0.5 mL)
Time/ s
( ±0.005s)
Trial 1 Trial 2 Trial 3
Average
Volume
0 100.0 100.0 100.0 100.0
600 94.7 95.3 96.0 95.3
Volume/mL (±0.5 mL)
Time/ s
(±0.005s)
Trial 1 Trial 2 Trial 3
Average
Volume
0 100.0 100.0 100.0 100.0
600 91.0 89.7 91.0 90.6

9. Koz 9
Table 6: Change of Mass of Ethanol and Isopropyl
Type of Alcohol/ Mass of Ethanol and Isopropyl/g (±0.01)
Ethanol &
Isopropyl
Trial 1 Trial 2 Trial 3
Average
Mass
Ethanol 1 2.66 2.65 2.61 2.64
Ethanol 2 5.36 5.28 5.43 5.36
Isopropyl 1 2.66 2.67 2.63 2.65
Isopropyl 2 10.38 10.59 10.32 10.43
Table 6 shows initial and final mass of wick for ethanol and isopropyl alcohol. (Ethanol 1:
Initial Mass of Wick for the Ethanol, Ethanol 2: Final Mass of Wick for the Ethanol,
Isopropyl 1: Initial Mass of Wick for the Isopropyl, Isopropyl 2: Final Mass of Wick for the
Isopropyl)
Calculation 5: Take the average of the all values.
Calculation 6: The combustion enthalpy of the alcohol has to be calculating in 600th
second.
The equation of energy is like followings.
𝑄 𝐴𝑏𝑠𝑜𝑟𝑏𝑒𝑑 𝑏𝑦 𝑊𝑎𝑡𝑒𝑟 = 𝑄 𝐴𝑏𝑠𝑜𝑟𝑏𝑒𝑑 𝑏𝑦 𝐴𝑙𝑐𝑜ℎ𝑜𝑙
𝑚 𝑤𝑎𝑡𝑒𝑟 × 𝑐 𝑤𝑎𝑡𝑒𝑟 × ∆𝑇 = 𝑄 𝐿𝑜𝑠𝑡
For this experiment, the mass of pure water has to be known.
𝑚 𝑤𝑎𝑡𝑒𝑟 = 𝑑 𝑤𝑎𝑡𝑒𝑟 × 𝑉 𝑤𝑎𝑡𝑒𝑟
𝑑 𝑤𝑎𝑡𝑒𝑟 = 1 𝑔 𝑐𝑚−3
and 𝑉 𝑤𝑎𝑡𝑒𝑟 = 200 𝑚𝐿

10. Koz 10
𝑚 𝑤𝑎𝑡𝑒𝑟 = 𝑑 𝑤𝑎𝑡𝑒𝑟 × 𝑉 𝑤𝑎𝑡𝑒𝑟
𝑚 𝑤𝑎𝑡𝑒𝑟 = 1 × 200 = 200 𝑔
Calculation 7: The value of ΔT is not change according to the K or °C. The value of this ∆T
for this experiment is equal to;
∆𝑇 = 48.8 (±0.01) − 18.7(±0.01) = 30.1 𝐾 ± 0.02
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 ∆𝑇 =
0.2
30.1
= 0.7 %
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 𝑀𝑎𝑠𝑠 =
0.01
200.0
× 100 = 0.05%
𝑐 𝑤𝑎𝑡𝑒𝑟 = 4.18 𝐽 𝑔−1
𝐾−1
200 (0.05 %) × 4.18 × 30.1(0.7 %) = 𝑄 𝐺𝑎𝑖𝑛𝑒𝑑
𝑄 𝐺𝑎𝑖𝑛𝑒𝑑 = 25163.6 𝐽 = 25.2 (±0.75) 𝑘𝐽
Calculation 8: For the calculation of enthalpy of ethanol, following equations can be applied.
𝑉𝑜𝑙𝑢𝑚𝑒 𝐶ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 = 100 (±0.5) − 95.3 (±0.5) = 4.7 ± 1.0
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 𝑉𝑜𝑙𝑢𝑚𝑒 =
1.0
4.7
× 100 = 21.2%
𝑑 =
𝑚 𝑀𝑎𝑠𝑠 𝑜𝑓 𝐴𝑙𝑐𝑜ℎ𝑜𝑙
𝑉𝑈𝑠𝑒𝑑 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 𝑓𝑜𝑟 𝐶𝑜𝑚𝑏𝑢𝑠𝑡𝑖𝑜𝑛
𝑑 = 0.789 𝑔 𝑐𝑚−3
≅ 0.8 =
𝑚
4.7(21.2%)
𝑚2 = 0.8 × 4.7 (21.2%) = 3.8 (21.2%)
The mass of ethanol has to be calculated as like following equation;

11. Koz 11
∆𝑚 𝐸𝑡ℎ𝑎𝑛𝑜𝑙 = 𝑚2−𝑚1
where the m1 is the mass of alcohol that is absorbed by wick and m2 the mass of alcohol that
is used for combustion and absorbed by wick.
𝑚1 = 5.36 (±0.01) − 2.64 (±0.01) = 2.72 𝑔 (±0.02)
∆𝑚 𝐸𝑡ℎ𝑎𝑛𝑜𝑙 = 3.80 (±0.01) − 2.72 (±0.02) = 1.08 𝑔(±0.03)
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 𝑀𝑎𝑠𝑠 =
0.03
1.08
× 100 = 2.7%
Calculation 9: To calculate the enthalpy of the ethanol;
(1 𝑚𝑜𝑙 𝑜𝑓 𝐸𝑡ℎ𝑎𝑛𝑜𝑙)𝑚 𝑤 = 46.1 𝑔
𝑛 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 =
𝑚
𝑚 𝑤
𝑛 =
1.08 (2.7 %)
46.1
= 0.02 𝑚𝑜𝑙𝑒 (2.7 %)
∆𝐻 𝐶
°
=
∆𝐻
𝑛
=
25.2 𝑘𝐽 (8 %)
0.02 𝑚𝑜𝑙𝑒 (0.8 %)
= 1260 (8.8 %)
𝐸𝑟𝑟𝑜𝑟 % =
|𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝑅𝑒𝑠𝑢𝑙𝑡 − 𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒|
𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒
× 100
|1260 − 1360|
1360
× 100 = 7.0 %
Calculation 10: The combustion enthalpy of the alcohol has to be calculating in 600th
second.
The equation of energy is like followings.

12. Koz 12
𝑄 𝐴𝑏𝑠𝑜𝑟𝑏𝑒𝑑 𝑏𝑦 𝑊𝑎𝑡𝑒𝑟 = 𝑄 𝐴𝑏𝑠𝑜𝑟𝑏𝑒𝑑 𝑏𝑦 𝐴𝑙𝑐𝑜ℎ𝑜𝑙
𝑚 𝑤𝑎𝑡𝑒𝑟 × 𝑐 𝑤𝑎𝑡𝑒𝑟 × ∆𝑇 = 𝑄 𝐿𝑜𝑠𝑡
For this experiment, the mass of pure water has to be known.
𝑚 𝑤𝑎𝑡𝑒𝑟 = 𝑑 𝑤𝑎𝑡𝑒𝑟 × 𝑉 𝑤𝑎𝑡𝑒𝑟
𝑑 𝑤𝑎𝑡𝑒𝑟 = 1 𝑔 𝑐𝑚−3
and 𝑉 𝑤𝑎𝑡𝑒𝑟 = 200 𝑚𝐿
𝑚 𝑤𝑎𝑡𝑒𝑟 = 𝑑 𝑤𝑎𝑡𝑒𝑟 × 𝑉 𝑤𝑎𝑡𝑒𝑟
𝑚 𝑤𝑎𝑡𝑒𝑟 = 1 × 200 = 200 𝑔 ± 0.01
Calculation 11: The value of ΔT is not change according to the K or °C. The value of this ∆T
for this experiment is equal to;
∆𝑇 = 40.8 (±0.01) − 18.2 (±0.01) = 22.6 𝐾 ± 0.02
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 ∆𝑇 =
0.2
22.6
× 100 = 0.9 %
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 𝑀𝑎𝑠𝑠 =
0.01
200.0
× 100 = 0.05%
𝑐 𝑤𝑎𝑡𝑒𝑟 = 4.18 𝐽 𝑔−1
𝐾−1
200 (0.05 %) × 4.18 × 22.6 (0.9 %) = 𝑄 𝐺𝑎𝑖𝑛𝑒𝑑
𝑄 𝐺𝑎𝑖𝑛𝑒𝑑 = 18893.6 𝐽 ≅ 18.9 (±0.95) 𝑘𝐽
Calculation 12: For the calculation of enthalpy of isopropyl alcohol, following equations can
be applied.

13. Koz 13
𝑉𝑜𝑙𝑢𝑚𝑒 𝐶ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 = 100 (±0.5) − 90.6 (±0.5) = 9.4 ± 1.0
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 𝑉𝑜𝑙𝑢𝑚𝑒 =
1.0
9.4
× 100 = 10.6%
𝑑 =
𝑚 𝑀𝑎𝑠𝑠 𝑜𝑓 𝐴𝑙𝑐𝑜ℎ𝑜𝑙
𝑉𝑈𝑠𝑒𝑑 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 𝑓𝑜𝑟 𝐶𝑜𝑚𝑏𝑢𝑠𝑡𝑖𝑜𝑛
𝑑 = 0.786 𝑔 𝑐𝑚−3
≅ 0.8 =
𝑚
9.4 (10.6%)
𝑚3 = 0.8 × 9.4 (10.6 %) = 7.52 (10.6 %)
The mass of ethanol has to be calculated as like following equation;
∆𝑚 𝐸𝑡ℎ𝑎𝑛𝑜𝑙 = 𝑚3−𝑚4
where the m4 is the mass of alcohol that is absorbed by wick and m3 the mass of alcohol that
is used for combustion and absorbed by wick.
𝑚4 = 10.43 (±0.01) − 2.65 (±0.01) = 7.78 𝑔 (±0.02)
∆𝑚𝐼𝑠𝑜𝑝𝑟𝑜𝑝𝑦𝑙 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 = 7.78 (±0.01) − 7.30 (±0.02) = 0.48𝑔 (±0.03)
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑈𝑛𝑐𝑒𝑟𝑡𝑎𝑛𝑖𝑡𝑦 𝑜𝑓 𝑀𝑎𝑠𝑠 =
0.03
0.48
× 100 = 0.6%
Calculation 13: To calculate the enthalpy of the isopropyl alcohol;

14. Koz 14
(1 𝑚𝑜𝑙 𝑜𝑓 𝐼𝑠𝑜𝑝𝑟𝑜𝑝𝑦𝑙 𝐴𝑙𝑐𝑜ℎ𝑜𝑙)𝑚 𝑤 = 60.1 𝑔
𝑛 𝐴𝑙𝑐𝑜ℎ𝑜𝑙 =
𝑚
𝑚 𝑤
𝑛 =
0.48 (0.6%)
60.1
= 0.01 𝑚𝑜𝑙𝑒 (0.6 %)
∆𝐻 𝐶
°
=
∆𝐻
𝑛
=
18.9 𝑘𝐽 (0.95 %)
0.01 𝑚𝑜𝑙𝑒 (0.6 %)
= 1890.0 (1.55 %)
𝐸𝑟𝑟𝑜𝑟 % =
|𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝑅𝑒𝑠𝑢𝑙𝑡 − 𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒|
𝐴𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑉𝑎𝑙𝑢𝑒
× 100
|2021 − 1890.0|
2021
× 100 = 6.48%
Graph 1: The Temperature Change of Water during the Combustion of Ethanol
Graph 1 shows average temperature change during the combustion of ethanol for 10 minutes.
Graph 2: The Temperature Change of Water during the Combustion of Isopropyl Alcohol
y = 0,0478x + 21,032
R² = 0,988
0
10
20
30
40
50
60
-100 0 100 200 300 400 500 600 700
Temperature/°C(±0.1)
Time/ s (±0.005)

15. Koz 15
Graph 1 shows average temperature change during the combustion of isopropyl alcohol for 10
minutes.
Qualitative Data:
1. The beaker of the ethanol is hotter than the isopropyl alcohol.
2. There is no color change during the experiment.
3. The CO2 bubbles can be observed on the surface of the pure water.
4. The CO2 released from the water.
5. Another source of the CO2 which came from the alcohol released.
y = 0,0371x + 19,191
R² = 0,9945
0
5
10
15
20
25
30
35
40
45
50
0 100 200 300 400 500 600 700
Temperature/ºC(±0.1)
Time/s (±0.005)

16. Koz 16
CONCLUSION
This experiment investigates the relationship between molecular weight and molar
combustion enthalpy of alcohols which are ethanol and isopropyl. As hypothesis refers to if
the molecular weight of alcohol increases, then the molar combustion enthalpy of alcohol
increases.
In this experiment, 100 mL different types of alcohols added into the oil lamp and 200 mL
pure water heated. The temperature of the pure water measured in the 0th
, 1st
, 2nd
, 3rd
, 4th
, 5th
,
6th
, 7th
, 8th
, 9th
and 10th
minutes and recorded. Consequently, the data is as follows:
According to the Table 2 the mean temperature of combustion of ethanol in the 0th
, 1st
, 2nd
,
3rd
, 4th
, 5th
, 6th
, 7th
, 8th
, 9th
and 10th
minutes which are 18.7 °C, 23.5 °C, 28.2 °C, 30.4 °C,
33.6°C, 36.0 °C, 38.3 °C, 41.3 °C, 43.9 °C, 46.3 °C and 48.8 °C respectively. In this
experiment QGained has to be equal to the QLost, thus 𝑄 = 𝑚 × 𝑐 × ∆𝑇 formula applied as
shown in Calculation 6, Calculation7, Calculation 8 and Calculation9. For the calculation of
the molar heat of ethanol, used amount of the ethanol has to be known. Thus, the initial and
final volume of ethanol are 100 mL and 95.3 mL respectively as shown in the Table 4 and the
wick absorb the alcohol during the combustion of ethanol and initial and final mass of wick
measured which are 2.64 g and 5.36g as shown in the Table 6. According to the data the used
amount of ethanol is calculated. 1 mol ethanol has 46.01 grams as mention in the background
information and according to the information, used amount of ethanol in terms of mol
calculated as shown in the Calculation 7.
According to the Table 3 shows the mean temperature of isopropyl alcohol in the 0th
, 1st
, 2nd
,
3rd
, 4th
, 5th
, 6th
, 7th
, 8th
, 9th
and 10th
minutes which are 18.2 °C, 21.1 °C, 23.8 °C, 27.0 °C,
28.3°C, 30.5°C, 32.9 °C, 34.8 °C, 37.0 °C, 39.1 °C and 39.1 respectively. 𝑄 = 𝑚 × 𝑐 × ∆𝑇
formula applied as shown in Calculation 10, Calculation 11, Calculation 12 and Calculation
13. For the calculation of the molar heat of isopropyl, used amount of the isopropyl has to be

17. Koz 17
known. Thus, the initial and final volume of isopropyl are 100 mL and 90.6 mL respectively
as shown in the Table 5 and the wick absorb the alcohol during the combustion of isopropyl
and initial and final mass of wick measured which are 2.65 g and 10.43 g as shown in the
Table 6. According to the data the used amount of isopropyl is calculated. 1 mol isopropyl has
60.10 grams as mention in the background information and according to the information, used
amount of isopropyl in terms of mol calculated.
According to the calculations, Graph 1 and Graph 2 sketched. The difference between initial
and final temperature observed from the graphs. Uncertainties of the temperature and
chronometer added in the axis. There are no anomalous data for that experiment. All data
closed to each other as shown in the graphs.
According to the observations (qualitative data), Table 2, Table 3, Table 4, Table 5, Table 6
Graph 1 and Graph 2 the experiment data are accurate. Thus, results support the hypothesis
and the experiment results are reliable. If the experiment had seen further repetition, more
appropriate results would have been at hand.

18. Koz 18
Table 7: Limitations and Improvements
LIMITATIONS IMPROVEMENTS
The system can be more isolated. The room conditions can be close to the original
values.
The location of the thermometer always changed
because thermometer did not stay constant in the
beaker.
Thermometer can be staying constant by the aid
of the materials.
The mass of wick measured by the scale but wick
absorbed the alcohol.
The wick can be press more.
REFERENCES
Anonymous, (n. d.) “Ethanol” (16 January 2014) No city of Publication: ChemSpider. Royal
Society of Chemistry. Retrieved from: <http://www.chemspider.com/Chemical-
Structure.682.html>
Anonymous. (n. d.) “Isopropyl Alcohol” (20 September 2013) USA: National Institute of
Standards and Technology, Materials Measurement Laboratory. Retrieved from:
<http://webbook.nist.gov/cgi/cbook.cgi?ID=C67630&Mask=20>
Neuss, G. (2007) IB programme chemistry course companion. Oxford University Press, New
York

19. Koz 19
Tro, N. J. (2011) Chemistry a molecular approach second edition. Westmont College, Upper
Saddle River, New Jersey. 07458, 2008 Pearson Education.