• 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
6. 6
6
7. 7
7

# In my investigation I will measure the heat given out by different types of primary alcohols when combusting with oxygen and compare the difference in the energy out put per mole of different alcohols.

Extracts from this document...

Introduction

GCSE CHEMISTRY COURSEWORK

Aim:

In my investigation I will measure the heat given out by different types of primary alcohols when combusting with oxygen and compare the difference in the energy out put per mole of different alcohols.

Hypotheses

Before we can have a look at the heat content of the different alcohols, we must be able to understand the process of combustion, the changes of the energy within the system while combusting with oxygen and how to determine the difference of the energy given out per unit.

First it is crucial to know that it is the external energy that we are measuring of the system, because as the Second Law of thermodynamics states that heat cannot be completely converted into work without some part of the system undergoing change, a equation is applied to the law illustrates that H (total heat content) = G (free energy) + TS (temperature×entropy, TS is the unfree energy which is associated with the degree of disorder of the system), and H can only be equal to G when TS=0 which only takes place at the temperature of absolute zero. We therefore cannot measure the total change in enthalpy (total heat content) since the 3rd law of thermodynamics states that absolute zero cannot be reached; the entropy which measures the degree of disorder also increases spontaneously that the particles of the system become disorderer or more random. What this investigation measures is the spontaneous change in the free energy which is converted into heat as stated in the second law of thermodynamics.

Then it is necessary to know that the reaction is exothermic that is heat

Middle

Tin canHeat proof mat

(See photo 1)

Method

In order to carry out this investigation, two measurements must be taken; they are the loss in the weight of the alcohols, and the temperature change of the water. Subsequently before we can start the experiment we must measure the weight of the spirit burner, and record the reading. Then the stand boss and the clamp should be set up to fix the tin in place. The reason why I have chosen the tin to be the calorimeter is because it is a good conductor to heat thus it has a relatively low heat capacity, and more kinetic energy can be passed to the water molecules efficiently to make accurate my results. The spirit burner should be positioned directly beneath the tin and a heat proof mat is needed to be placed under the spirit burner. The distance between the peak of the wick and the bottom of the tin must be kept constant in order to carry out a fair comparison. A draught shield is needed to be placed around the spirit burner and the tin to prevent the unnecessary heat loss that could vary the result of the experiment. (See photo 2) After the apparatus have been set up as described above, then we must measure 200ml of water of 2×100ml measuring cylinder and add which to the tin, and then place the thermometer to the water and wait until the reading is stable. It important to keep the volume of water constant since the energy required to raise 1oc is associated with the mass. This stable reading can give the actual temperature

Conclusion

As well as to discover the pattern among the primary alcohols, secondary and tertiary alcohols can also be investigated. We already know the relationship between the numbers of carbon atoms or the length of the carbon chain and the energy output, it would be equally significant to learn the science when the carbons are not in a chain or a irregular chain, and how a hybridized carbon if any at all is able to alter the results. Investigations could be among propan-2-ol, butan-2-ol, pentan-2-ol, hexan-2-ol, cyclohexanol and 2-methyl-propan-2-ol.

Coursework completed by Lu Xiao (Adrian) in November 2002-12-2

Bibliography: “Advancing Chemistry” of Oxford University Press by Michael Lewis and Guy Waller, “Chemistry for you” by Lawrie Ryan, “Chemistry, a practical approach” by , and “www.creative-chemistry.org”

Acknowledgements from D.G.Galbreath PhD and Mr. S.D.Penthreath M.A.

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism 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 Electricity and Magnetism essays

1. ## Investigation into Energy Released From Burning Various Alcohols.

4 star(s)

This would be because I cannot measure all the energy that is released, as some will be dispersed into the air, and also into the apparatus, such as the beaker, clamp, and thermometer. I will also be using Propan-2-ol, which has a different isomer to the other results.

2. ## To investigate which fuel gives out the most energy when burnt. We are burning ...

* Heat mats (draft shields) In my preliminary, a lot of heat was lost due to the flicker of the fuel's flame. Energy was also lost to the surroundings. In my actual I will be placing heat mats on wither sides of the experiment, to try and reduce the amount of energy lost through the flicker of the fuel's flame.

1. ## &amp;quot;My aim is to find out how much energy is released when burning different ...

Mass of water (20cm ) X Temp difference X 4.2 = Energy Released J/_______g J/________g mass of crisp (J/1g) X 100 (J/100g) 1000 (KJ/100g) = Energy Released from 100g of crisp KJ/100g. Average Energy Released per 100g French Fries: 168 + 105 +161 KJ/100g = 434 3 = 144.7 Peak

2. ## Factors Affecting the Efficiency of a Wind Turbine

However, the most efficient shape is the most commonly used on wind machines already. The question still remains on how to improve the efficiency of wind turbines further. STEPS TAKEN WHILE CONDUCTING THIS INVESTIGATION FROM THE BEGINNING TO THE END Safety precautions Before each experiment the following had to be

1. ## Electromagnetism - investigating what effect increasing the number of turns in a coil on ...

have used a compass, I would move the compass at shot distances away from the electromagnet until the compass was first effected by the magnet If I was to keep the same method I would pay more attention to the temperature and try keep it the same throughout my experiment

2. ## Finding a material's specific heat capacity

The specific heat capacity assumed for water will be taken to be 4192.5 J kg-1 K-1 as this is its specific heat capacity at about 11.5�C which is the roughly the average temperature of the distilled water during the copper's period of linear temperature increase.

1. ## Investigating the heat of combustion of a series of Alcohols

672 C - O = 40 X 336 = 13440 O - H = 2 X 464 = 928 C - C = 8 X 346 = 2768 O = O = 15 X 497 = 7455 Total Energy in = 21393 kJ Total Energy out = 24576 kJ Energy

2. ## My aim is to measure the specific heat capacity of 4 metals and find ...

The Results! Brass! 5.30s Over 50 C is the highest temp. Time Every 30s Temp In C Starting temp = 20 1/2 Amps Voltage 4.00s 42 power pack off - 0.01 - 0.00 Copper! 4.30s 43 power pack off - 4.89 - 13.56 5.30s Over 50 C is the highest temp.

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