The Combustion of Ethanol and Paraffin Wax
Purpose: To test the amount of heat gained by the paraffin candle in comparison to the heat gained by the ethanol in the reaction of combustion.
Hypothesis: When the temperature increases, the paraffin candle would be able to gain more heat because it have more covalent bond compared to ethanol
Procedure:
Experimental errors occurred in this experiment due to the limitation on the accuracy of the materials. Such as we can’t get 175ml of water so we modified it t 176 ml, because it is hard to get an accurate measure of water when it forms a concave meniscus in the graduated cylinder. This result in the measure for water for paraffin wax is off by 1ml. Then after many attempts to collect water, the water temperature stays at 15.5C, 5.5C higher than the objective of around 10C, making the final temperature to be as high as 40.5C. Other than that, the soda can was elevated to about 4cm above the flame, much too high compared with 2cm. So heat escaped through the crevasses on the bottom of the tin can or the edge of the tin can and the soda can to the air instead of warming up the water. So many heat is lost to the air than being absorbed by the water. When the candle solidifies after the experiment, it formed a concave meniscus around in the aluminum because the central part of the candle was the closest to the flame and it burnt smaller. Compared to the normal candle, the candle looked smoother and translucent after the experiment. The bottom of the soda turned slightly more to the colour of reddish copper.
Observation/Data Table:

Before
During
After
C20H46
paraffin candle
Pure white, opaque, brittle solid with no smell at room temperature
Clear, colourless and transparent liquid. A burning smell is produced, temperature increased as well as heat is released
Liquid resolidifies, gradually turns from opaque to white, top turns meniscus and color is more grey white
C3H6
ethanol
Clear and colorless liquid that is transparent, strong pungent ,acrid smell
Slowly evaporating while blue flame fades off
Ethanol evaporated
H2O
water
Clear, colorless, odourless transparent liquid
Temperature increases as it was heated
Water temperature increased

Quantitative Table:
Substance
Mass (g)
Temperature(C)
Volume(ml)
Paraffin candle
B:9.76
A:8.26

ethanol

50.0
3.0
Water for paraffin candle

B:15.5
A:40.5
176
Water for ethanol

21.5
176

Calculations:
1. combustion of water
a) Mass of water is 176 g
b) 25C
c) 176*4.18*25=18392(J)
2. Combustion of candle
a)1.5g
b) 25/1.5=16.7(J/g C)
3. Combustion of ethanol
a) Mass of ethanol is 3.0g
b) 50.0-21.5=28.5(c)
c) 3.0*0.7893*28.5=67.485 (J)
4. a) 3.0g of ethanol consumed by the combustion
b) 67.485/3.0=28.5(J/g)

Discussion:
1. Ethanol +oxygen gas= carbon dioxide+ water
C2H6O+2O2---2CO2+3H2O
2.The candle demonstrate complete combustion because there is sufficient oxygen going through the air holes on the bottom of the tin can and this provides the oxygen for the burning process.
3. Wax is a better fuel, this is because paraffin wax has a boiling point higher than 370C and the ethanol has a boiling point that is of 38C. So paraffin wax is solid while ethanol is liquid at room