This website uses cookies to ensure you have the best experience. Learn more

Thermochemistry Essay

662 words - 3 pages

Thermochemistry is the application of thermodynamics to chemistry.Thermochemistry is used to predict the energy exchanges that occur in the following processes:1. chemical reactions2. phase changes such as boiling and melting3. the formation of solutionsThermochemistry is primarily concerned with the following state functions defined in thermodynamics:Internal energy (U)Enthalpy (H).Entropy (S)Gibbs free energy (G)Most identities in Thermochemistry arise from application of the first law of thermodynamics, the Law of Conservation of Energy, to these state function.In chemical reactions, bonds are broken and reformed, and heat may be given off or taken up in such processes. Since reactions are often carried out at constant pressure, the change in enthalpy is the appropriate measure of heat given off or absorbed.Laws of Thermochemistry1. The magnitude of H is directly proportional to the amount of reactant or product.-Thus H can be used as a conversion factor in a balanced equation to obtain amounts of reactant/product or H itself. (mole to mole ratio's).2. H for a reaction is equal in magnitude but opposite in sign to H for the reverse reaction.Heats of FormationMolar heat of formation ( Hf) is equal to the enthalpy change, H when one mole of the compound is formed from the elements in their stable forms at 25oC and 1 atm is Ho (pronounced 'delta h naught'). Ho of a solution is of a 1M solution, at 1 atm and 25 oC.Heats of formation are usually negative quantities.Heat is a way of transferring energy between a system and its surroundings that often, but not always, changes the temperature of the system. Heat is not conserved, it can be either created or destroyed. In the metric system, heat is measured in units of calories, which are defined as the amount of heat required to raise the temperature of one gram of water from 14.5oC to 15.5oC.In the SI system, the unit of heat...

Find Another Essay On Thermochemistry

Lab Report Discovering Which Common Nut is the Best Heat Source when Burned

2979 words - 12 pages temperature interval is sometimes specified in other ways. The definition now generally accepted in the United States, and standard in thermochemistry, is that 1 cal equals 4.1840 joules (J). A slightly different calorie is used in engineering, the international calorie, which equals 1/860 international watt-hour (W h). A large calorie, or kilocalorie (Cal), usually referred to as a calorie and sometimes as a kilogram calorie, equals 1000 cal and is

When the Bubble Burst Essay

1539 words - 6 pages By the time I arrived state side from my second tour in the Middle East the housing bubble had already burst. I noticed a drastic change in the way that many of my friends and family were living. Several of my friends that worked in real estate had sold their boats and seconds houses. My own stock portfolio had lost a third of its value. My sister and her husband had defaulted on their home mortgage leaving them scrambling for a place to live. I

phase diagram

4456 words - 18 pages Introduction: Chemical equilibrium is a crucial topic in Chemistry. To represent and model equilibrium, the thermodynamic concept of Free energy is usually used. For a multi-component system the Gibbs free energy is a function of Pressure, Temperature and quantity (mass, moles) of each component. If one of these parameters is changed, a state change to a more energetically favorable state will occur. This state has the lowest free energy

Revolutionary Work of Art

1890 words - 8 pages Walter Benjamin emphasizes in his essay, “The Work of Art in the Age of its Technological Reproducibility” that technology used to make an artwork has changed the way it was received, and its “aura”. Aura represents the originality and authenticity of a work of art that has not been reproduced. The Sistine Chapel in the Vatican is an example of a work that has been and truly a beacon of art. It has brought a benefit and enlightenment to the art

Enlightenment Thought in New Zealand Schools

1594 words - 6 pages In this essay I will be looking at how the political and intellectual ideas of the enlightenment have shaped New Zealand Education. I will also be discussing the perennial tension of local control versus central control of education, and how this has been affected by the political and intellectual ideas of the enlightenment. The enlightenment was an intellectual movement, which beginnings of were marked by the Glorious Revolution in Britain

Psychological Egoism Theory

2240 words - 9 pages The theory of psychological egoism is indeed plausible. The meaning of plausible in the context of this paper refers to the validity or the conceivability of the theory in question, to explain the nature and motivation of human behavior (Hinman, 2007). Human actions are motivated by the satisfaction obtained after completing a task that they are involved in. For example, Mother Teresa was satisfied by her benevolent actions and

How Celtic Folkore has Influenced My Family

1587 words - 6 pages Every family has a unique background that influences the way they live and interact with other people. My parents, who emigrated from Ireland to the States with my three brothers in 1989, brought over their own Celtic folklore and traditions that have helped shaped the way our family operates and lives. One aspect of folklore that has helped shape my family dynamic is the Celtic cross—both its background and what role it has played in our lives

Julia Margaret Cameron

1406 words - 6 pages At a time when women were looked upon as being homemakers, wives, mothers and such the late 1850's presented a change in pace for one woman in specific. Photography was discovered in 1826 and soon after the phenomenon of photography was being experimented with and in turn brought new and different ways of photo taking not only as documenting real time, but also conceptualizing a scene in which an image would be taken. Julia Margaret Cameron will

Evaluation of School Improvement

1403 words - 6 pages The evaluation process should be progressive to incorporate overall planning, implement changes, which contribute to success. In order to focus on school climate and norms, the evaluation design must include the students, instructions, and outcomes to improve communication and building-level concerns to be address in this response. School Climate and Social Norms The school principal, other staff leaders, and personnel set the tone and the

Case Study: The Benefits of Animal Testing

1757 words - 7 pages Nine year old Amy has already had a rough start in life. She was born with an abnormal heart that hinders her everyday activities. Amy is unable to keep up with kids her own age because she often tires out easily. As a consequence, she has very little friends and is often alone. Amy is forced to take different medications everyday just to survive. Amy’s life consists of medicine, doctors, and constant hospital visits. However, Amy is due for a

Myth and Magic: Realism in "One Hundred Years of Solitude"

1531 words - 6 pages “He enjoyed his grandmother's unique way of telling stories. No matter how fantastic or improbable her statements, she always delivered them as if they were the irrefutable truth” (Wikipedia, 2011). Experiences are particular instances of one personally encountering or undergoing something and in these moments of time life changes for the best or the worst and memories are formed. These recollections such as riding your first bicycle, going to

Similar Essays

Should All Plastics Be Biodegradable? Essay

983 words - 4 pages degrade is biodegradable plastics. However, are biodegradable plastics the answers to the addiction to plastic people have? Arguments have been made on whether the pro’s of biodegradable plastics outweigh the cons and if biodegradable plastics will truly make a difference in our environment. Survey Results Chemistry Connections Thermochemistry is the study of the energy changes that accompany physical or chemical changes in matter. Biodegradable

Seperating Cyclohexane And Toluene By Distillation Understanding Perceptual Sets

903 words - 4 pages ) Boiling point 80.74 °C (353.74 K) Solubility in water Immiscible Viscosity 1.02 cP at 17 °C Thermochemistry Std enthalpy of formation ΔfH o298 -156 kJ/mol Std enthalpy of combustion ΔcH o298 -3920 kJ/mol Hazards MSDS External MSDS EU classification Flammable (F) Harmful (Xn) Dangerous for the environment (N) Severe eye irritant, may cause corneal clouding R-phrases R11, R38, R65, R67, R50/53

History Of Chemistry Essay

1103 words - 5 pages pupil of Stahl’s, had identified an impurity in copper ore as a separate element. Axel had discovered nickel. He was also the founder of modern mineralogy, and in 1751, he also discovered the mineral scheelite, tungsten. Joseph Black had isolated carbon dioxide in 1754. He soon called carbon dioxide “fixed air.” In 1758, joseph used a concept called latent heat to show the thermochemistry of phase changes. Henry Cavendish had isolated hydrogen in

Spectroscopy Of Atoms Lab Essay

1826 words - 8 pages , chemistry of solids • Organic Chemistry Topics covered in the studio laboratory include: • Using Physical Properties to Identify Unknowns • Determination of Avogadro’s Number • Stoichiometry and Chemical Formulas • Identifying Salts Using Precipitation Reactions • Determining Water Hardness by Titration • Thermochemistry: Fuels • Gases: Pressure, Volume, and Temperature • Oxidation of Metals and Hess’s Law • Lewis Structures and