• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5

# If There Is a Relationship Between the Number of Carbon Atoms In Several Different Alcohols and the Heat of Combustion of Those Alcohols.

Extracts from this document...

Introduction

Planning Experimental Procedures Introduction In this experiment, I plan to discover if there is a relationship between the number of carbon atoms in several different alcohols and the heat of combustion of those alcohols. I would also like to discover the nature of the relationship(if there is one). For example: if the heat of combustion increases or decreases with the number of carbon atoms and by how much. Apparatus Retort stand, boss, clamp, tin can, water, six alcohols (methanol, ethanol, propanol, butanol, pentanol, hexanol.) in burners, Bunsen burner, heatproof mat, thermometer (0 - 100�c), digital scales. Method 1. Set up the retort stand as shown above. 2. Record the starting temperature of the water (100ml). 3. Take the first alcohol - in a burner - and weigh it on digital scales. Record the weight. 4. Light the wick on the burner and allow it to burn until the temperature of the water in the can has risen by 20�c. WEAR GOGGLES AS HEAT IS BEING USED! 5. Re-weigh the burner and record its new weight. 6. Calculate the change in weight since lighting. 7. Repeat steps 2 - 6 twice more. 8. Repeat steps 2 - 7 for each of the other alcohols. ...read more.

Middle

There are five such bonds in ethanol so you multiply 410 by five to get 2050 joules. You do these calculations for all the other types of bonds that make up ethanol, add them all together and you get 3270 joules. All of the other alcohols can be broken up in this way. Below is a table showing the energy required to break up the bonds in each alcohol. Type of Alcohol Energy required to break bonds(j) Methanol 2100 Ethanol 3270 Propanol 4440 Butanol 5610 Pentanol 6780 Hexanol 7950 As you can see a longer molecule is, the more energy it takes to break its bonds. I can come to predict that the longer the molecular structure in the alcohol the more energy it will take to break the bonds. I also predict that the increase in energy required will be proportional to the number of extra carbon atoms. With each new carbon atoms that you add to the chain, you also add two new hydrogen atoms. Apart from this, the chain remains unchanged. I therefore predict that the energy required to break the bonds will increase by 1170 joules for each new carbon atom. Obtaining Evidence Summary of Results (First Repeat) ...read more.

Conclusion

Radiation of heat out into the atmosphere. 3. The fact that the tin can gets hot. 4. The rubber clamp transferred heat way. 5. By incomplete combustion 6. The activation energy to get the alcohol burning. 7. The availability of alcohol for the wick to burn, if not enough then the wick would burn not the alcohol which would give an inaccurate result. 8. Evaporation of water so there will be less water to heat, making the water hotter. 9. The size of the wick. 10. Not all of the water was the same temperature. 11. The flame size changed due to the type of alcohol, hence it was a different distance away from the beaker each time. I could obtain a better picture of how the number of carbon atoms affects the heat of combustion in two ways. 1. I could extend my current experiment by testing other alcohols such as heptanol or octanol as well as by doing more repeats to increase the accuracy of my results. 2. I could conduct a similar experiment with other homologous series of hydrocarbons such as the alkanes or the alkenes. This would allow me to compare the results from each experiment and compare how the number of carbon atoms in the chain affects the heat of combustion. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Organic Chemistry section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Organic Chemistry essays

1. ## Experiment to investigate the heat of combustion of alcohols.

4 star(s)

on a graph and another graph was plotted, from the calculated bond energies that were present in my planning before. However there are 2 other graphs that were plotted from the original data before it was averaged. Here is the calculated energy change, which is a little simplified to save time and space.

2. ## The Combustion of Alcohols and the factors affecting these reactions

This will include appropriate apparatus: * Volumes will be calculated to the nearest cm� using the measuring cylinder. * Masses will be recorded to 2 d.p.using the digital scales. * Heights being measured to the nearest millimetre with a ruler.

1. ## How Does The Increase In The Length Of The Carbon Chain Affect The Energy ...

break more bonds and also for some new bonds to be made. By looking at the experimental results on the graph, it can be seen that the increase in enthalpy change is proportional to the length of the carbon chain.

2. ## Investigating the Combustion of Alcohols

The table below shows the number of different bonds in the each of the molecules that undergo combustion - alcohol, oxygen and the combustion products, carbon dioxide and water. The significance of this will be shown later in the analysis section.

1. ## Combustion of Alcohols

I have to use one alcohol to keep the test a fair one, this is because all alcohols burn differently and produce different amounts of heat.

2. ## Determination of the heat of combustion of alcohols

Wire gauze should not be used, since it will absorb part of heat. 5. The thermometer should not touch the bottom of the aluminium can and should use it to stir water gently to distribute heat uniformly. 6. Placing the alcohol lamp on a metal tray to prevent spillage

1. ## Comparing the enthalpy changes of combustion of different alcohols.

Below you will find the revised results for the experiment. Pentan-1-ol Replicate one Replicate two Replicate three Weight of spirit burner before (g) 206.18g 204.73g 203.85g Weight of spirit burner after (g) 204.73g 203.30g 202.41g Change in mass of spirit burner (g) 1.45g 1.43g 1.44g Starting temperature of water (�C)

2. ## Comparing Energy Given When Different Alcohols Burn.

it should be 3 cm long and not to thick * Dip the top of the wick in to the alcohol, this helps it light * Place under the calorimeter * Measure the distance between the top of the wick and the base of the calorimeter, it should be 10

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to