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IV:,DV:
IV: type of alcohol
DV:the heat of combustion
Aim:
To investigate the difference of the heat of combustion for three different types of alcohols
Hypothesis:
It is hypothesized that if the alcohols have a higher molar mass then the heat of combustion will increase.
Conclusion:
In conclusion this experiments purpose was to investigate the difference of the heat of combustion for three different types of alcohols.As the results collected show, the alcohol with the higher molar mass will have a higher heat of combustion, for example methanol has the highest molar mass 60gmol and it has the highest heat of combustion.Therefore the hypothesis was supported as it states that if the alcohols have a higher molar mass then the heat of combustion will increase.
Qualitative or quantitative data?
Quantitative data (or numerical data) can be precisely measured and have values that are expressed in numbers. Line graphs or scatterplots are often used to display the frequencies of numerical variables which is used for experiment
Accuracy and precision:
Accuracy can be measured by the formula actual heat of combustion(in data booklet)/foundx100
This experiment was somewhat precise however due to a random error that affected the experiment
Accuracy refers to how close an experimental measurement is to a known value. If an archer is accurate, for example, their arrows hit close to the target. Consider an experimental calculation of the boiling point of water, which is known to be 100 °C. A student who obtained an experimental value of 99 °C is more accurate than a student who obtains a value of 105 °C.
Precision refers to how close multiple measurements of the same investigation are to each other. Note that results that are precise may not be accurate. It is often difficult to have completely precise results due to random errors(made by me).
Analysis:
-There was a positive correlation, increasing amount of molar mass led to an increasing amount of heat of combustion
-There was an out outlier which was caused my a personal error due the the fact that the experiment was not observer for a bit
Assumptions include:
-All controlled variables are actually controlled
-Reparations would result in similar accurate results as they would be similar or identical
-Assumed it would be complete combustion
-Equipment gave precise and accurate results
-Assumed all the energy released by the heat of combustion of the fuel is used to heat the water however some is lost to surroundings
limitations include:
-room temperature, contaminants or humidity
-harder to control variables and use specialised equipment that may improve accuracy and precision, and limit errors and uncertainty.
-Can’t control all variables
-Small sample
-Not being able to repeat
Some of the questions you should explore when evaluating data include:
Does the data provide an answer to the question of your investigation?
Does the data support or refute your hypothesis?
If any outliers, errors or uncertainty were present in your data, why may these have occurred?
Can your data be linked to different models and theories that are presently supported?
Could you make further adjustments to improve your data in future investigations that may reduce errors or limitations?
Partial oxidation
Partial oxidation occurs when the oxygen is fed at a level below that which is needed for complete oxidation, and produces hydrogen and carbon monoxide.for this experiment soot black substance was released which means that incomplete combustion is occurring as the black substance was carbon .
interpolation
predict data within the data that was measured
extrapolation
data beyond range ex. points outside the data that was measured
