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Enthalpy of paraffin wax Lab

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Introduction

Chemistry Enthalpy of Paraffin Wax lab Aim: Calculate an experimental value for the enthalpy of Combustion of paraffin wax Variables Independent variable: Amount of heat released by the combustion of paraffin wax Dependant variable: Enthalpy of combustion of paraffin wax Controls: The candle used to release energy must be the same throughout the experiment, to ensure that the wax is the same. This will be done by only using one wax candle The aluminium can used to heat up the water must remain the same so that it's mass does not change due to the carbon molecules on the bottom from the heat and so that no water escapes the system. ...read more.

Middle

Measure the temperature of the water in the can and note it down 4. Place the candle below the can (which is suspended above it using a clamp attached to a pole) 5. light the candle 6. Wait around 5 minutes before noting down the temperature of the water 7. blow out the candle and push it aside carefully and swiftly 8. Take the mass of the candle and note it down in your datatable. 9. Weigh the can with the water, take the final mass down and jot down how much water was lost during the procedure 10. Repeat steps 1 to 9 for the second trial Datatable Trial 1 Trial 2 Initial temperature of water (c) ...read more.

Conclusion

Second Experimental Value for enthalpy of combustion (Kj/mol) Theoretical Value for enthalpy of combustion (Kj/mol) -10613.63 -10027.5 -13774 Reasons for difference : Improvements More trials could be done We could time the amount of time the paraffin wax candle burns to give us more even values Water was lost when removing and placing the thermometer, this could be avoided by having the thermometer in the water the whole time, but then the thermometer would absorb the heat as well. Sources of error : Some water and paraffin wax was lost to then environment during the experiment, this can not be changed. Some of the heat was escaping to the atmosphere from the candle, this could not be improved because the candle needs oxygen to burn so we could not place it in an insulated environment. ...read more.

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