An Investigation Into The Factors Affecting Loss Of Heat From Alcohols.

Authors Avatar

An Investigation Into The Factors Affecting Loss Of Heat From Alcohols

Planning

My aim for this experiment is to see the energy produced of different alcohols.

Variables involved:

For this experiment I would expect to have 3 different variables, Independent, Dependent, and fixed variables, which all helps me to plan and explain the experiment thoroughly.

The Independent variable (things you change), the thing that I will be changing in this experiment into the combustion of a range of alcohols, would be five different alcohols, Methanol, Ethanol, Propanol, Butanol, and Hexanol, which will help me to investigate combustion of different alcohols. I will measure these individual alcohols by mass which will be measured in grams, I'll be making two readings of each alcohol before the experiment and after, which would tell me the mass lost and how much heat in produces in 5 minutes.

Dependent Variable (things that you measure) the things that I'll be measuring would be the temperature (oC) increase by every minute of each different alcohol being lit to heat the water in the copper calumeter, and the mass before and after the experiment of alcohols.

Fixed Variables (Things that you keep the same) the things that I have chosen to keep the same in each individual experiment to keep it a fair test, is to keep the same amount of water being heated, the same copper calumeter (as it may very in conductivity), the height of the calumeter, and the same amount of time for each experiment. This would help me to compare and analyse the results of the individual experiments.

Hypothesis:

My prediction for this experiment on investigating the energy produced by different alcohols is that, the longer the hydrocarbons in the chain of the alcohols, the more heat it will produce. As the alcohols are being lit by the waxy splint that produces heat, it will also give out oxygen and water as well as heat energy to heat the water, which will crack the hydrocarbons into simpler molecules (smaller) and then will combust later, making this experiment an exothermic reaction. Therefore the long chains of hydrocarbons produce more energy than smaller chain molecules as the long chain breaks in to smaller hydrocarbons meaning theirs more, making the boiling point decrease, which makes them more flammable, less viscous, and more volatile. Therefore I would expect that when the alcohol's is being burned and producing heat energy, carbon dioxide, and water will be produced meaning the alcohol would lose some mass which would evaporate into the air. I therefore predict that when there is a longer chain of hydrocarbons than another alcohol, it would produce more heat than the other alcohol meaning it would have a higher reading each minute compared to a smaller chain of hydrocarbons, which could mean that the smaller hydrocarbons combust quicker then longer hydrocarbons as their less volatile.

Scientific explanation of what would happen:

When each alcohol is burned to give out energy to heat the copper flask I would expect each of the following would happen to each alcohol I have listed below. Looking at all the alcohol's I have noticed that they're all alkanes, which means that they all have single bonds. This means that the alcohol's are made up of chains of carbon atoms with single covalent bonds between them, which are called saturated hydrocarbons because they have no spare bonds left meaning they won't form polymers. All the five alcohols would have complete combustion, which relates to this equation below.

Join now!

Hydrocarbon + water carbon dioxide + Water (+ energy)

Methanol (CH3OH) would burn with a very clean flame, produce the least amount of energy as they have the least amount of hydrocarbons. This is because they only have 1 carbon atom, which combust in the shortest amount of time, out of the 4 other alcohols.

This is the complete combustion balanced equation showing methanol heated with carbon dioxide and water.

CH3OH + 11/2O2 CO2 + 2H20

Ethanol (C2H5OH) will burn with a very clean flame, produce the second least amount of heat energy as they have the second least amount of hydrocarbons. ...

This is a preview of the whole essay