The Enthalpy Change of Different Alcohols

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The Enthalpy Change of Different Alcohols

My aim is to compare the enthalpy change of combustion of different

alcohols in relation to the structure of each molecule.

The enthalpy change of combustion of a fuel is a measure of the energy

transferred when one mole of the fuel burns completely. In a chemical

reaction, bonds must either be made or broken, this involves an

enthalpy change. The formation of bonds is exothermic, energy is lost

to the surrounding; on the other hand, breaking bonds is endothermic,

energy is taken in. I obtain the value for the enthalpy change of each

fuel by using the formula:

Energy transferred from the fuel=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

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