Effect of an Increase in Molar Mass on Enthalpy Change

Effect of an Increase in Molar Mass on Enthalpy Change An investigation to determine the effect of an increase in molar mass on the enthalpy change of combustion of fuels Method Variables: Independent Variable: Molar mass (type) of alcohol. Dependant Variable: The following variable will be observed and measured: * Mass of the alcohol used. Controlled Variable: The following variables will need to be controlled: * Mass of water, the mass of water will be measured using a measuring cylinder. * Amount of wick on burner, the amount of wick on the burner will be measured using a standard ruler and kept constant as it affects the amount of alcohol burnt. * Height of beaker above flame, the beaker will be set up so that the base just touches the flame. * Type of beaker, the same beaker will be used and marked, as the density and size of the beaker affect the amount of heat energy transferred to the water. * Agitation of the water, the water will need to be stirred in every experiment as to prevent any anomalous results. * Temperature change is held constant, measured with a thermometer reading from -10oC to 110oC, with an uncertainty of  ±0.5oC Method Procedure: 1. Measure 100cm3 of water in the measuring cylinder. 2. Pour the water into the 250cm3 beaker and record its temperature. 3. Choose a spirit burner. Record the name of the fuel, and the mass of the whole burner (including the lid and fuel inside). 4. Clamp the beaker, and set it up so that the spirit burner will fit comfortably under it. 5. Light the 6mm wick of the spirit burner, and put it under the 250 cm3 beaker. 6. Stir the water gently with the thermometer, and watch the temperature. When it has increased by 20 °C, put the lid on the spirit burner to put the flame out. 7. Record the new mass of the whole burner (including the lid and fuel inside). 8. Using fresh water each time, repeat the experiment at least twice with the same fuel. 9. Repeat all for different fuels. Result: Quantitative raw data: Fuel Name Experiment 1 Experiment 2 Temperature Mass Before/g ( ±0.01) Mass After/g ( ±0.01) Mass Before/g ( ±0.01) Mass After/g ( ±0.01) Before/oC ( ±0.05) After/oC ( ±0.05) Methanol 181.48 180.00 179.79 178.22 20.00 40.00 Ethanol 215.64 214.50 214.52 213.50 20.00 40.00 Propan-1-ol 228.70 227.39 227.39 225.91 20.00 40.00 Butan-1-ol 174.63 173.96 173.96 173.34 20.00 40.00 Pentan-1-ol 172.33 171.47 171.47 170.84 20.00 40.00 Octan-1-ol 218.77 217.72 217.72 216.85 20.00 40.00 Observations during Experiment: All reactions were exothermic as the beaker and the surrounding began to warm up. Fuel Name Observation Methanol It burnt with a short dim orangey yellow flame. The base of the beaker was partly covered with soot. Small bubbles formed at the base of the beaker. Ethanol It burnt with a pale orangey yellow flame. The base of the beaker was slightly darkened by the formation of soot. Small bubbles formed at the base of the beaker. Propan-1-ol It burnt with a thin bright orangey yellow flame. The base of the beaker was again slightly darkened by the formation of soot. Small bubbles formed at the base of the beaker. Butan-1-ol It burnt with a narrow and long yellowish orange flame. The base of the beaker was considerably darkened by the formation of soot. Small bubbles formed at the base of the beaker. Pentan-1-ol It burnt with a narrow and long yellowish orange flame. The base of the beaker was completely darkened by the formation of soot. Small bubbles formed at the base of the beaker. Octan-1-ol It burnt with a narrow and long distinct yellow flame. The base of the beaker was fully obscured by the formation of soot. Small bubbles formed at the base of the beaker. Analysis: The heat that is released in the combustion of an alcohol is absorbed by the liquid. The temperature change of the liquid is then related to the heat of combustion of the alcohol (heat released in a reaction (combustion in this case) = heat gained by the substance). I can work out the heat energy absorbed by the liquid using the formula: Heat Energy transferred (Q) = mà ¢Ã‹â€ Ã¢â€ž ¢cà ¢Ã‹â€ Ã¢â€ž ¢Ãƒ ¢Ã‹â€ Ã¢â‚¬  T c = specific heating capacity of water (4.18 Jg-1K-1) m = mass of water (in grams) à ¢Ã‹â€ Ã¢â‚¬  T = change in temperature of the water. And find the enthalpy (heat) change of combustion per fraction of a mole of the alcohol. For example: Mass of water (m) = 100g ( ±0.5), Change in Temperature (à ¢Ã‹â€ Ã¢â‚¬  T) = 20.00 °C ( ±0.10) Therefore, Heat Energy Transferred (Q) = mà ¢Ã‹â€ Ã¢â€ž ¢cà ¢Ã‹â€ Ã¢â€ž ¢Ãƒ ¢Ã‹â€ Ã¢â‚¬  T (degree of uncertainty) = 100 à ¢Ã‹â€ Ã¢â€ž ¢ 4.18 à ¢Ã‹â€ Ã¢â€ž ¢ 20 ( ±0.5 +  ±0.10) = 8360 J ( ±0.6) = 8.36 kJ ( ±0.6) This is the same for every reaction as the mass of water remains constant. From here on, I can calculate the enthalpy change per fraction of a mole of the substance as it combusts to form its products: à ¢Ã‹â€ Ã¢â‚¬  Hc Alcohol + Oxygen → Carbon Dioxide + Water Mass of Methanol used = 1.52g ( ±0.02) Number of moles (N) = M/RMM (percentage degree of uncertainty) = 1.52g / 32.04g ( ±2.00% +  ±0%) = 0.0474 mol ( ±2.00%) Where, M = Mass of the Alcohol used to heat the amount of water RMM = Relative Molar Mass of the Alcohol obtained from the data book, so the percentage uncertainty is  ±0% à ¢Ã‹â€ Ã¢â€ž ¢Ãƒ ¢Ã‹â€ Ã¢â€ž ¢Ãƒ ¢Ã‹â€ Ã¢â€ž ¢ Enthalpy change of Combustion (à ¢Ã‹â€ Ã¢â‚¬  Hc) = Q/N (percentage degree of uncertainty) = 8.36 kJ / 0.0474 mol ( ±7.17% +  ±2.00%) = 176.22 ( ±9.17%) All calculations are done similarly. Fuel Name Average Initial mass/g ( ±0.01) Average Final mass/g ( ±0.01) (M) Mass used/g ( ±0.02) (à ¢Ã‹â€ Ã¢â‚¬  T) Temp change/ °C ( ±0.10) (Q) Heat Energy Transferred/kJ ( ±0.12) (N) Number of Moles used/mol ( ±2.00%) (à ¢Ã‹â€ Ã¢â‚¬  Hc) Enthalpy change of Combustion ( ±9.17%) /kJ mol-1 Methanol 180.64 179.11 1.52 20.00 8.36 4.74 x10-2 -176.22 Ethanol 215.08 214.00 1.08 20.00 8.36 2.34 x10-2 -356.62 Propan-1-ol 228.05 226.65 1.40 20.00 8.36 2.33 x10-2 -358.82 Butan-1-ol 174.30 173.65 0.65 20.00 8.36 0.88 x10-2 -953.29 Pentan-1-ol 171.90 171.16 0.75 20.00 8.36 0.85 x10-2 -982.58 Octan-1-ol 218.25 217.29 0.96 20.00 8.36 0.74 x10-2 -1134.09 Conclusion: From the table it is evident that the molar mass of an alcohol increases the amount of heat energy it dispenses per fraction of a mole. Also, the graph shows that there is a positive correlation between molar mass and enthalpy change of combustion for alcohols. What could explain the relation is that as the molar mass increases there is an increase in the number of available carbon atoms to combine with oxygen and release energy. Therefore, an increase in molar mass will have an incremental effect on the enthalpy change of combustion. Evaluation: Fuel Name Literature à ¢Ã‹â€ Ã¢â‚¬  Hc Value (LV) Experimental à ¢Ã‹â€ Ã¢â‚¬  Hc Value (EV) Literature error (EV – LV)/LV*100 Methanol -726.00 -176.22 75.76% Ethanol -1367.30 -356.62 74.00% Propan-1-ol -2021.00 -358.82 82.24% Butan-1-ol -2675.60 -953.29 64.38% Pentan-1-ol -3328.70 -982.58 70.48% Octan-1-ol -5293.60 -1134.09 78.58% Table depicting the percentage error of the experimental value from the actual value available in the data book Average Literature error: 74.22% The results are not consistent with the literature values, all of the reactants did not completely combust due to the lack of oxygen, leading to the formation of soot and carbon monoxide, which means that the heat output is less than it would have been if all of the carbon burnt, since the calculations are based on the mass of the un-burnt carbon, the calculated value is less than the literature value. The beaker would not have transferred all the heat across; some would have been lost in heating the beaker as well as the clamp and stand, this would have caused the value to be less than the actual value. Other possible sources of error could be by slight differences in the values of the fixed variables, like the mass of water not being exactly 100g, due to incorrect reading of the measuring cylinder caused by a parallax (when the scale is read at an angle to the eye, as the light is refracted through the glass, the reading appears to be at a different position). The same error could have been also made in the reading of the thermometer, causing there to be wrong temperature readings. There were some anomalies when reading the graph as two values were almost identical. It could have been due to the amount of wick on the burner as it would not have been exactly the same (6mm) on each burner as this was difficult to measure. This would have caused differences in the amount of alcohol burnt. The flame was not always just touching the beaker, as this again was difficult to measure accurately, and would have caused differences in the amount of heat given off as the temperature of the flame is different at different heights. Also, the thermometer was not in the same place at each temperature recording, as even though the water was stirred, there would be differences in the temperature of the water at different depths. Errors mentioned in conducting Experiment Possible corrections that could be made Incomplete Combustion of reactants Placing the fuel in an airtight chamber and controlling the flow of air through valves as to make the correct stoichiometric balance ratio of carbon and oxygen. Heat loss to the surrounding Insulation of the beaker, boss, clamp and stand by wrapping them with polystyrene. Also, Preventing any draught from carrying the heat energy away by placing a board to shield it. Parallax error Position of eye at all volumetric vessels must be at the same level as the meniscus. Transfer of heat energy to the liquid A calorimeter made of a better heat conducting material, perhaps something strong and lightweight like aluminium.

Hypodermic needle Essay

Preface As I sat down to think about this research paper I thought about chocolate and all the things I could write about and they all seem to be the same thing. Where chocolate came from, and how it was made as well as how do you cook with it and even some chocolate recipes. I wanted to do something that I thought had never been done before, be original I hope that this is something that you haven’t seen before in a research paper. Introduction Chocolate can be constructed in many different ways. Besides of using it in sculpting and shaping, it can be imprinted with patterns and cut into shapes for cake decoration. But in today’s world many invention has taken place in the chocolate industry over the past few years. Here are some of the new ways that chocolate is being use in technology. 1. The Chocolate Whiff David Edwards a Harvard professor has patented a new way to consume chocolate: called Le Whif it is made up of a tube that sprays a mist of chocolate. It delivers one kilocalorie (calorie) per spray; this invention gives the healthy-conscious a way to satisfy their chocolate cravings without the gilt. 2. A Chocolate Printer At Cornell University a scientist has created a 3-Demintional food printer that can print using hypodermic needles filled with chocolate. The printer not only can do chocolate, but also any edible ingredient that can be put in liquid form. The needles act in combination with computer to create layers which slowly become a 3-Demintional object. 3. Chocolate meets Fashion Because of its molding capabilities chocolate Stacey Van Waldick of Promise Me Chocolates a chocolate company in New York has created chocolate gems, rings and pendants for party favor wedding and special occasion, while one a year New York City presents a Fashion show called â€Å" The Chocolate Show† where all the clothing are made up of chocolate. 4. The Chocolate that is a Vitamin Every body knows about how eating chocolate is supposed to release endorphin to the brain which helps to release stress. But now there is a company in Northern California that has begun to put polyunsaturated acids like omega-three as well as immune booster in chocolate. This will help to increase the health benefits of eating chocolate. 5. Chocolate that you can listen to. I know what you are thinking but the answers in â€Å"No† chocolate can’t speak, but Ben Milne a baker from Scotland was try to find a way to help his friends promote their album when he decided to put the band’s music on a chocolate record, after that made a playable chocolate CD. Now that is the real meaning of â€Å"the sweet sound of music†. 6. No-melting chocolate The melting point of chocolate is between 86 °-90 ° right? Wrong because there is a company in Ireland that has the patent to what is said to be the world’s first chocolate that does not melt. The clam is that chocolate has oils in it that makes it bendable and resistant to heat. The Play-dough like chocolate can easily be used by pastry chiefs, comes in three different varieties milk white and dark and, and it is totally digestible. 7. Technology meets chocolate Based out of San Francisco California TCHO (Technology+Chocolate) is an up and company that produces chocolate with an different flare Timothy Childs founder was an NASA software programmer who decided to strike out on his on with a vision to make chocolate from scratch and in doing so here created what he calls the TCHO dark chocolate flavor wheel which consists of flavors like chocolately, citrus, nutty, earthy, fruity and floral. Childs also invented an iphone app that he can log on to and control his flavor lab by remote he can control time, temperature and shut the machines off and on. Conclusion With technology changing by the day the thought of what can be done with chocolate is now unlimited. Where is chocolate going â€Å"The World will never know? † Bibiliograpy â€Å"Apple – IPhone in Business – Profiles – TCHO Chocolate. † Apple – IPhone in Business – Profiles – TCHO Chocolate.N. p. , n. d. Web. 30 Nov. 2012. . â€Å"Chocolate and Technology Deliciously Mix in California. † Fox News. FOX News Network, 17 July 2012. Web. 30 Nov. 2012. . â€Å"5 Surprising Chocolate Innovations. † Menuism Dining Blog RSS. N. p. , n. d. Web. 30 Nov. 2012. . N. p. , n. d. Web.

Realism Paper

Brandon Jackson There are many differences between realism and theatricalism. Realism consists of any type of play that is based off of real life events. And theatricalism is the complete opposite. It doesn’t consist of any real life events and they aren’t supposed to do such. Realism plays don’t have to have any sort of originality but they are normally written directly from real life events. When play writers are writing a realistic play they tend to write the play as common and close to everyday speech and actions of humans. Realistic plays almost always recall on flashbacks, which consist of scenes that occurred in the characters past.In realistic plays actors and actresses do not even look directly at the audience, many of times in these plays actors do not even acknowledge the audience’s presence in order to give it that realistic feel. Take the play Joe Turners come and gone for example the characters sway away from keeping in contact with the crowd and they make sure not to look at the audience for any reason. If I where to write a play on the realism of a high school students way of speaking, I would be sure to use a lot of slang in my speech to make it as realistic as possible.As said before the play Joe Turners come and gone is a great example of realism. The play shows the struggles of an African American family and consists of real live events like slavery and poverty. The characters are all working class who are barely making a living. Another realistic play, which consists of realistic event, is The Piano Lesson. Just like Joe Turner’s Come and Gone, the characters in The Piano Lesson are all working class African Americans working hard just to survive.The main character Boy Wille is so desperate for money he decides he wants to trade a piano that has been in the family for several years in order to acquire land for crop growing. But the play does use some theatricalism. Towards the end of the play they make a g host a ghost which many could agree isnt exactly realism. But even within the play they still seem to make the story very believable with a realistic. The same with The Last Five Years. This play and or musical are very realistic and utilize many different scenes of the everyday life of a married couple in Ohio.Unlike the Play Joe Turners come and gone, Angles in America is completely un realistic and is clearly imaginary. There are many aspects of Thearicalism found in this play. Nothing in this play is predictable and throughout the play the audience can be found both confused and some amazed by its creativity. Absurdism is another aspect of theatricalsim. Absurdism is the philosophical thought of people are meaningless and have no job or role in life. Many Fictional plays normally consist of some sort theatricalism and many Absurdism. Expersionalism is the thought of painting a picture with words and or in the form of a play.This can be seen in almost any play because theatre is a form or art and the main objective of any play is to paint a picture. But in any Thearticalism play the Every aspect of these plays are make believe, and they normally don’t consist of a true plot and or seem realistic. The use of Imagery and exaggeration and distortion can be found in just about any theatrical play. http://www. musicomh. com/theatre/last-five-years_0706. htm http://www. sparknotes. com/drama/piano/summary. html http://dictionary. reference. com/browse/theatricalism NOTES

Women Archetypes in Greek Ancient Pantheon

Women Archetypes in Greek Ancient Pantheon The notion of an archetype is rather complicated and has multiple layers, since it is widely used in many spheres of modern psychology and culture. The definition of the term has undergone several changes in the course of the cultural evolution. Within the frames of the current essay, it is possible to define an archetype as a generic, cumulative image, possessing some certain characteristic features. Before our civilization switched to the patriarchal social systems with male gods, there existed a single and united image of a Woman – the Great Goddess, who was the symbol of life and death, closely related to the nature and fertility. She was responsible for the creative power of life, as well as for the destructive forces. In the Greek pantheon there existed 7 goddesses, who represented the most common archetypical models of female behaviors. Aphrodite, Demeter and Hera were the most powerful ones. They had more deep connection with the Great Goddess archetype, than the other four. Aphrodite is a weaker variant of the Great Goddess in her fertility avatar. In Demeter we can easily find her Mother feature, whereas Hera is the echo of the Great Goddess as the Heaven Empress. Altogether they represent irresistible forces in every woman’s soul that make her such a unique creature as she is. Artemis, Athena and Hestia are so-called Virgin goddesses. They represent female independence. They are not apt to love or emotional attachment, considering these outpouring to be distracting for their major activities, and express female need for independence and social life. Persephone is the personification of a Daughter – a young woman, who is still on her way to emotional maturity. Thus, all these archetypes are inevitable components of the psychical structure of a woman.