Investigating the enthalpy change of different alcohols

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Investigating the enthalpy change of different alcohols

 

Method

            In this investigation I am going to try to find out if there is a relationship between different lengths of alcohol chains and their combustion enthalpy change. I am going to do this by using spirit burners and a calorimeter. I will burn the fuel until it has heated up the water in the calorimeter until it is a certain temperature, then I can use the heat capacity of the water and the molecular formula of the alcohol to work out the enthalpy change.

            Here is my draft method:

 

Equipment:

        Aluminium can to act as calorimeter, about 10cm in diameter and able to hold about 200ml of water.

        0-50°c thermometer (or 0-110°c if 0-50°c not available).

        200ml measuring cylinder.

        Spirit burners containing:        Methanol

Ethanol

                                                         Propan-1-ol

Butan-1-ol

        Balance (accurate to 2 decimal places).

        Clamp stand, clamp, heat mats.

 

Set-up:

 

 

 

 

 

 

 

 

 

 

Method:

1.      Record temperature of water in calorimeter.

1.      Weigh spirit burner and record.

1.      Light spirit burner.

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1.      Keep burner lit until the temperature of the water is 20°c higher and record.

1.      Put out the spirit burner.

1.      Weigh spirit burner again and record.

 

This is a crude method therefore we did some preliminary testing to find out where improvements can be made and to find out the optimal dimensions e.g. wick height and calorimeter height.

 

These are the amendments we made to get the best results by making the experiment more accurate:

        When measuring the amount of water to go in calorimeter I made sure that I measured it at room temperature ...

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