Thursday, January 30, 2020
In the 15th Century the idea of schooling began Essay Example for Free
In the 15th Century the idea of schooling began Essay It is used during the process of streaming within school subjects. For example pupils who the teacher feels is good or poor at a certain subject, will be taught in a high or low ability group, this has criticisms at it encourages pupils to think of themselves as having fixed educational ability. A pupil can also be given a label from their behaviour, such as trouble maker or thick, either at home or school. This can damage a childs self esteem or make them rebel, which leads to them believing the label they have been given, this is called the Self-fulfilling prophecy. For what ever reason they were given the label, they find it hard to be looked at without the label, so end up behaving in a way that fits to their given label. Working class not only have had inequalities in the past but also still do today. Although there are more opportunities in the education system, home life also plays large impact on how well a child does achidemically at school. Douglas (1964) conducted a study on middle and working class children through primary and secondary school. He found that children of a similar measured ability at age 7 varied a great deal in their educational achievement by the time they were 11. He claimed that the greatest influence on attainment was parental attitudes in the working class. He measured this by the number of times these parents visited the school, family size, early child-rearing practises, health and the quality of the childs school. Working class children are more likely to have a part time job whilst at school and likely to leave education at 16. The Plowden Report (1967) noticed in working class households there was an absence of books, educational toys, lack of finance, lack of motivation, no parent support of due to own experiences or as a need to work long hours. This has been described as Material and Cultural deprivation. Jackson and Marsden (1962) published a study, Education and the working class. It showed that working class children tend to be slower in learning how to read and write, they start school at a disadvantage and this normal continues throughout. Marxists would say that this is because there are less opportunities for some classes and that the education system just helps to reproduce the existing class structure, e. g. , the ruling class (upper and middle class) and the workers (the working class), thus conflict and inequalities will continue. Success at school depends heavily on language, for reading, writing, speaking and understanding. Bernstein argues that there is a relationship between language use and social class, and that the language used by the middle class is a better instrument for success at school than the language used by the working class, (Browne 2005). In his view there are two different language codes: Ã The restricted code- This language is used by both classes, but is more characteristic of the working-class people. It is used everyday amongst friends and family, which is informal and simple (such as slang). Bernstein argues that lower-class-working people are mainly limited to this form of language use. Ã The elaborated code- This is mainly used by the middle-class, and is spoken in a formal context, with explanation if required. It has a much wider vocabulary than the restricted code, and is the language that would be found in textbooks, essays and examinations. Bernstein has argued that as the language used in schools by teachers and in textbooks is the elaborated code, working class children are disadvantaged. They may find it hard to understand the elaborate language used in school, therefore their work will suffer. Unlike middle class children who are used to the language so will find the work easier. Differences have been found amongst the achievements of people from different ethnic backgrounds, possible reasons for this could be the differences in their cultural backgrounds, language barriers and understanding or suffering from racism. If English were not the first language for someone this would give him or her a large disadvantage in the understanding of the language, which would affect their work in most areas. Suffering from racism in or out of school would cause the pupil upset, which could affect their schoolwork. Many Pakistani, Bangladeshi and African Caribbean children have large families and are working class, so are likely so have deprived social conditions. These groups mentioned appear to have a below average reading ability and tend to get fewer and poorer GCSE results than white or Indian pupils. It can be seen on the below table they are the overall lowest achieving ethnic groups. Students that achieved 5 or more GCSE grades A*-C (%) Race Group 1989 1998 2002 Indian N/a 54 60 White 30 47 52 Bangladeshi N/a 33 41 Pakistani N/a 29 40 Black 18 29 36. (Department for Education and skills, 2004: in Livesley et al, 2005) From the data above it is clear that black children are the lowest achievers. In the past racist remarks have been made claiming that problem was they had lower levels of inherited intelligence. Which is untrue, in 1985 the Swann Report found that there was no significant difference between the IQs of black and white children, (Thompson et al, 1982). Black boys are often given labels such as unruly and difficult to control, due to how the teacher has interpreted them by their dress, manner or speech, and find them challenging. They are more often to be given detention than other pupils, and often feel unfairly treated, then respond in accordance with their label, self-fulfilling prophecy. Although they do not achieve well at school, the number of black women staying in education past the age of 16 is increasing, which may be influenced by the many future career opportunities available today. Kamala Nehaul (Parenting, Schooling and Caribbean Heritage Pupils 1999) has noted how black parents valued education for the enhanced life chances it offered. She also mentioned the encouragement and commitment from parents, talking about the school day and providing provisions needed for their child to study. Indian children do well within the education system, there is a strong emphasis on self-improvement through education within this culture. Many of these children have professional backgrounds, so have good role models and supportive parents and they also have material advantages. Differences in the achievement between gender, race and class will continue to be compared, though surely the person should be treated as an individual. Post-modern thinkers such as Elkind (1998), suggest a key characteristic here is the idea of difference and, in a sense, the fragment of identities. In other words, students want to be recognised and treated as unique individuals rather than as groups, (Livesey et al, 2005). Although a students background may effect their achievement, as evidence suggests, it must be remembered that everyone is an individual with their own abilities, no matter what race, class or gender they are, have the potential to achieve in education. A girl, black or white from a working class background may not have had any opportunities for a good career after education 50 years ago, due to inequalities in the system, but this is not the case today. Overall the educational achievements for all groups of people have improved. There will always be some people in all of the groups mentioned previously, that fail in education, as a result of self-gratification and now culture, they are more focused on living for the moment, and not thinking about how their actions during their education can effect their future life.
Wednesday, January 22, 2020
Capital Punishment is Murder Essay example -- Argumentative Persuasive
Capital Punishment is Murder Capital punishment is state-sanctioned, premeditated murder. It is morally, ethically, socially wrong. Murder is the intentional killing of one person by another. Capital punishment takes the life of one person and uses another, "the executioner," to do it. In the state of Indiana, the warden of the state prison acts as "the executioner." The killing takes place before the hour of sunrise on a fixed day. On that day, the warden, "executioner," flips a switch sending approximately 2,800 volts of electrical current into the body of the convicted prisoner, thus ending the prisoner's life. Upon completion of the execution, one person's life is intentionally ended by the act of another. The difference, however, is that this murder is condoned by the state. The state's Supreme Court, Appeals Courts, Superior Courts, and prosecutors all play an important role in condoning the use of capital punishment. Many precautions are taken to ensure that all due process rights are given to the offender; however, I wonder how many times we have executed innocent people. In June 1992, in the state of Virginia, a man was executed for the brutal rape and murder of his sister-in-law. Throughout his 11 year stay on death row, he claimed he was not guilty of this crime. We may never actually know the truth, yet his life was ended. If his innocence could be proven today, his punishment could not be reversed. Without a doubt, we have executed innocent people in this country. In fact, Hugo Bedau and Michael Radelet reported that 350 wrongly convicted persons have been sent to death row. ... ...e the prison's visiting room for his "daddy." How do you tell this precious, innocent child that his "daddy" is about to be killed in an electric chair? Who do you tell him is responsible for his "daddy's" death? How do you comfort a mother as she sits weeping the moments before her only son is to be executed? How, I wonder, do these people feel about "justice being served?" In my involvement with inmates on death row, I see the pain of their families as they go through the appeal's process, hoping and praying that their loved one's sentence will be overturned. The death experienced by this set of victims is a slow, long, drawn out death. Murder and capital punishment are synonymous. Both consist of the intentional killing of a human being. Both are morally, ethically, and socially wrong.
Tuesday, January 14, 2020
Chemistry Study Guide (Exam 2)
Examination #2 ââ¬â Chapters 4,5, and 6 Study Guide Chapter 4 ââ¬â Chemical Quantities and Aqueous Reactions * Reactions Stoichiometry * mole-mole conversions * mass-mass conversions * Limiting Reactants * What is the Limiting Reagent * How do we find the L. R. * Solutions * Molarity ââ¬â definition and how to calculate * Dilutions Calculations (M1V1 = M2V2, careful with M2) * Solution Stoichiometry * volume-volume conversions * volume-mass conversions * Molecular interpretation of solubility * solubility rules * Precipitation Reactions * Determining reaction products * Following Solubility rules Molecular Formula, Total ionic formula, net ionic formula * Acid-Base Reactions * Oxidation-Reduction reactions * Identify odixation states * Identify which species was oxidized and reduced Chapter 5 ââ¬â Gases * Pressure ââ¬â definition * Simple Gas Laws * Boyle's Law ââ¬â pV * Charles's Law ââ¬â P/T * Avogadro's Law ââ¬â nT * Ideal Gas Laws * pV=nRT * Densit y calculations * Molar Mass calculations * Molar Volume * Partial Pressures * Dalton's Law of Partial Pressures * Eudometer calculations * Gas Reaction Stoichiometry * Volume ââ¬â moles conversions * Kinetic Molecular Theory * 4 components of the theory * You DO NOT need to know the derivation of I.G. L. * Effusion of Gases * Real Gases * van der Waals equation * Your extra credit question will have to do with this topic! * Atmospheric Chemistry * 3 types of pollution-very, very basic question Chapter 6 ââ¬â Thermochemistry * Nature of Energy * System versus Surroundings * Definition of Energy, internal energy, law of conservation of energy * 1st Law of Thermodynamics * ? E = q + w * Sign convention, (is it positive or negative) * Heat and work * pV work * m Cs ? T heat transfer * conservation of thermal energy * Calorimetry * Constant volume calorimetry * only heat contributes to ? E * Enthalpy * Definition, equation Calculation using constant pressure calorimetry * Exother mic versus Endothermic reactions (sign of ? H) * Hess's Law * Enthalpy of reactions manipulations * This is a hard topic, please, please, please review this after Wednesday! Examination #2 ââ¬â Chapters 4, 5, and 6 Study Guide Chapter 4 ââ¬â Chemical Quantities and Aqueous Reactions * Reactions Stoichiometry * mole-mole conversions * Needs a balanced chemical equation * **Again no clear examples. Let me know if you can find any** * mass-mass conversions * **No clear examples. Let me know if you can find any** * Limiting Reactants * What is the Limiting Reagent The limiting reagent is also known as the limiting reactant. It is the reactant that limits the amount of product in a chemical reaction. Notice that the limiting reactant is the reactant that makes the least amount of product. * How do we find the L. R. * Example: * How many grams of N2 (g) can be produced from 9. 05 g of NH3 (g) reacting with 45. 2 g of CuO (s)? Create and Balance a Chemical Equation: 2NH3 (g) + 3CuO (g) N2 (g) + 3Cu (S) + 3H2O (l) 9. 05 g NH3 x 1 mol NH3 x 1 mol N2 x 28. 02 N2 = (7. 44 g N2) 17. 04 g NH3 2 mol NH3 1 mol N2 45. 2 g CuO x 1 mol CuO x 1 mol N2 x 28. 2 N2 = (5. 31 g N2 Less = LR Cuo is the Limiting Reactant! * Solutions * Morality ââ¬â definition and how to calculate * Definition: * Amount of solute (in moles) per amount of solution (in Liters) * Molarity (M) = Amount of Solute (in moles) Amount of Solution (in L) * **Side Note** * Homogenous Mixture = solutions (Salt Water) * Solvent (a component in a solution) : Majority component, what something is dissolved in. (Water) * Solute (another component in a solution) : Minority component, what is being dissolved (salt) * Example: What is the molarity of a solution containing 3. 4 g of NH3 (l) in 200. 00 mL of solution? Given: 3. 4 g of NH3M = moles of solute (NH3) 200. 00 mL L of Solution (200. 00 mL) Convert: 3. 4 g NH3 X 1 mol NH3 = (0. 20 mols NH3) 17. 04 G nh3 200 mL X 1 L = (0. 2L) 1000 mL M = 0. 20 mols NH 3 / 0. 2 L = 1. 0 M NH3 **More examples in Notes! ** * Dilutions Calculations (M1V1 = M2V2, careful with M2) * Diluting a solution is a common practice and the number of moles of solute will not change! [ (M1)(V1) = (M2)(V2) ] * Examples: What is the concentration of a solution prepared by diluting 45. mL of 8. 25 M HNO3 to 135. 0 mL? M1V1 = M2V2 8. 25 M HNO3 X 0. 045 L = M2 X 0. 135 L 0. 135 L 0. 135 L M2 = 275 M HNO3 * Solution Stoichiometry * volume-volume conversions * When using morality, you can easily extract moles! * With a balance chemical equation, you can convert between amounts of substances. * Exampes: Look at notes OR page 145 TB * volume-mass conversions * Examples: Look at notes OR page 145 TB * **This wasnââ¬â¢t clear and If you know what this means, let me know. Or else I will ask Donavan on Saturday (Because there wasnââ¬â¢t a specific section for the two bullet points) Molecular interpretation of solubility * solubility rules ââ¬â be familiar with the c hart/table that Prof. Donavan gave out 2 interactive forces that affect solubility: 1. solute-solute interaction 2. solute-solvent interaction if solute-solvent interactions are strong enough, solute will dissolve (solute-solvent interaction ; solute-solute interaction) * Precipitation Reactions * Determining reaction products General Form: AX (aq) + BY (aq) > AY (aq) + BX (s) Example: 2KI (aq) + Pb (NO3)2 (aq) >2KNO3 (aq) + PbI2 (s) * Following Solubility rules Molecular Formula, Total ionic formula, net ionic formula Examples: Molecular Formula: 2KOH (aq) + Mg(NO3)2 (aq) > 2KNO3 (aq) + Mg(OH)2 (s) Total ionic formula: * 2K+ (aq) + 2(OH)ââ¬â (aq) + Mg2+ (aq) + 2(NO3)ââ¬â (aq) > 2K+ (aq) + 2(NO3)- (aq) + Mg(OH)2(s) Net Ionic formula: (remove all spectator ions : ions that are aqueous as reactants and stay aqueous when they turn into products) Mg2+(aq) + 2(OH)-(aq) > Mg(OH)2(s) * Acid-Base Reactions General Form: HA (aq) + BOH (aq) > H2O (l) + BA (aq) Example: HCl (aq) + NaOH (aq) > H2O (l) + NaCl (aq) * Oxidation-Reduction reactions Oxidation is the loss of electrons * Reduction is the gain of electrons * Oxidation states: charges that allow us to keep track of electrons in chemical reactions * Identify oxidation states 1. Charge states of neutral compounds are zero 2. Charge of atoms in polyatomic ions need to add up to the total charge of the polyatomic 3. Keep Alkali metals as +1 alkali earth metals as +2 4. Keep F (fluorineââ¬â¢s) as -1 H as +1 O as -2 * Identify which species was oxidized and reduced * Look in last section of Chapter 4 Notes Chapter 5 ââ¬â Gases * Pressure ââ¬â definition Pressure: The force per unit area * Pressure comes from the constant interaction with a container * Standard Pressure = Normal Atmospheric Pressure * 760. 0 mm Hg = 1 atm * 760. 0 torr = 1 atm * 1. 000 atm * 101, 325 pa (pascals) = 1 atm * 14. 7 psi (lbs per square inch) = 1 atm * Example: * (45. 0 psi) x (101, 325 pa) x (1 k pa) ______________________ _______ = 310. kPa (14. 7 psi) x (1000 pa) * Simple Gas Laws * Boyle's Law ââ¬â pV * The volume of a gas inversely proportional to its pressure, provided the temperature and quantity of gas donââ¬â¢t change. * V= k/p Actual Equation: pV= K * Example: A balloon is put in a bell jar and the pressure is reduced from 782 torr to 0. 500 atm. If the volume of the balloon is now 2. 78 x 10^3 mL, what was it originally? V1 = 782 torr x 1. 000 atm/760 torr = 1. 03 atm (1. 03 atm)(V1) = (. 500 atms)(2. 78 x 10^3 mL) After Rearranging the equation: V1= 1350 mL or 1. 35 x 10^3 mL * Charles's Law ââ¬â P/T * The volume of a gas is diretly proportional to its temperature, provided the pressure and quantity of the gas that donââ¬â¢t change. (V= KT) **Temp in Kelvin Only** * For changes in Volume (involving temperature): * V1/T1 = V2/T2 For Changes in Pressure: * P/T (initial) = P/T (final) * Example: (LOOK IN NOTES ) * Avogadro's Law ââ¬â nT * The volume of a gas is directly propo rtional to the quantity of gas, provided the pressure and temperature of the gas donââ¬â¢t change. (V=Kn) * For changes in volume (involving moles) * V1/n1 = V2/n2 * Example: (LOOK IN NOTES ) * Ideal Gas Laws * pV=nRT * NEED TO KNOW THIS FORMULA! * P = pressure (atm) * V = volume (L) * n = quantity (moles) * T = temperature (K) * R = Universal Gas Constant * (0. 08206 Latm/molK) OR * (8. 314 J/molK) * Example: (look in notes ) Density calculations * Density of a gas @ STP: * For an Ideal gas @ STP, the molar volume = 22. 7 L * Density = mass/volume = mass/1mole = molar mass/molar volum * volume/1mole * Density for a gas NOT @ STP: * If gas isnââ¬â¢t at stp * Then D = P(MM)/ RT or D = m/v * Molar Mass calculations * From the equations: pV = mRT/MM You get: MM = mRT/ pV * Example (Look in notes ) * Molar Volume * At STP, all ideal gases take up the same volume. * Molar Volume = # of L of gas 1 mole of gas This also works: V/n = RT/P * Partial Pressures Dalton's Law of Partial Pr essures * The total pressure of a mixture of gases is the sum of the pressures by each gas. * The pressure of a gas would exert if it were alone in a container. * You can calculate the Partial Pressure from Ideal gas Law * If 2 gases , A and B are mixed together * P(A) = (nA)(R)(T)/ (V) and P(B) = (nB)(R)(T)/ (V) * Since R, T, and V are all constant for a mixture * P(total) = P(A) + P(B) = (nTotal)(R)(T)/ (V) * nTotal = sum of nA + nB * Example: (Look in notes ) Eudiometer calculations * An Eudiometer is a gas collecting Tube * Example: 2Zn (s) + 6HCl (aq) 3H2 (g) + 2ZnCl3 (aq) H20 (l) H2O (g) P(total) = P(H2) + P(H20) (value may be looked up at table 5. 4) * 0. 12 moles of Hz is collected over H20 in a total 10. 0 L container at 323 K. Find the total pressure. P = nRT/V P(H2) = (0. 12 mol H2) (0. 08206 Latm/molK) (323 K)= 0. 3181 am (10. 0L) P(total) = P(H2) + P(H20) P(H2O) @ 50 degrees Celsius = 92. 6 mmHg P(total) = 240mmHg + 96. 6mmHg = 330mmHg * Gas Reaction Stoichiometry * Gen eral Concept plan on most problems: P, V, T of Gas A Amount A (in moles) Amount B (in moles) P, V, T of Gas B * Volume ââ¬â moles conversions * Ex: Methanol CH3OH can be synthesized by the following reaction * CO2 (g) + 2H2(g) CH3OH(g) * What is the volume (in liters) of hydrogen gas @ a temperature of 355 K and pressure of 738 mmHG, is required to synthesize 35. 7 g of methanol * Given: 35. 7 g CH3OH temp: 355 K pressure: 738 mmHG * Find: V of H2 * 1. G of CH3OH mols * 35. 7g CH3OH x 1 mol CH3OH = 1. 1142 mol CH3OH 31. 04 g CH3OH * 2. Mol CH3OH mol H2 * 1. 11 mol CH3OH x 2 mols H2 = 2. 23 mols H2 1 mol CH3OH 3. N(mol H2), P, T VH2 * Convert your mmhg to ATM, and get . 971 atm * VH2= (2. 23 mol H2) (. 08206 l atm/ mol K) (355 K) = 66. 9 L .971 atm * VH2= 66. 9 L * Kinetic Molecular Theory * In this theory a gas is modeled as a collection of particles (either molecules or atoms depending on the gas ) in constant motion. * Ex, a single particle moves in a straight line until it co llides with another particle (or with the walls of its container). * 4 components of the theory 1. Particles are infinitely small and have no volume 2. Average kinetic energy of a particle is proportional to the temperature (k). . Particles travel in two straight lines following Newtonian Laws 4. All collisions are elastic (no attractive or repulsive forces) * You DO NOT need to know the derivation of I. G. L. * Effusion of Gases * Effusion: the process by which a gas escapes from a container into a vacuum through a small hole. * The rate of effusion (the amount of gas that effuses in an amount of time) is also related to the root mean square velocity * Rate is ? 1M * Grahms law of effusion: * The ratio of effusion rates of two different gases. * For example (look in notes, end of chapter 5) Real Gases * van der Waals equation is an equation used to correct for the discrepancies from the Kinetic Molecular Theory that real gases undergo. Real gases attract each other, therefore, real pressure ; ideal pressure. Real gases also take up space, therefore, real volume ; ideal volume. [P + a (n/v)? ] x (V ââ¬â nb) = nRT where: a ââ¬â corrects for molecular interaction. It makes the real pressure larger so it equals the ideal pressure b ââ¬â corrects for molecular size. It decreases the volume of the container. * Your extra credit question will have to do with this topic! * Atmospheric Chemistry 3 types of pollution-very, very basic question * 3 types of pollution-very, very basic question 1. Hydrocarbon combustion for automobiles 2C8H18 + 2SO2 > 16CO2 + 18 H2O At high temperature, nitrogen can also be combusted, which causes a problem. N2 + O2 > 2NO 2NO + O2 > 2NO2 (nitrogen dioxide) ââ¬â photochemical smog (causes problem in the environment) 2. Combustion of coal from power plants (Ex. Electrical cars) C + O2 > CO2 (Coal contains a significant amount of sulfur and it further combusts) S8 + 8O2 > 2SO3 2SO2 + O2 > 2SO3 SO3 + H2O > H2SO4 (H2SO4 results to acidification)But, people have found a way to eliminate the production of SO3 and that is by using ââ¬Å"clean coalâ⬠and scrubbers. CaCO3 + SO2 > CaO + CO2 CaO + SO2 > CaSO3 (s) (calcium sulfite) 3. Stratospheric Ozone O3 + UV > O2 + O (oxygen radical) O2 + O > O3 + IR These two equations above just shows how ozone is used and how it is just regenerated again. But, in 1974, Sherwood Rowland discovered that CFCs from air conditioners, refrigerators, and spray cans destroy the atmospheric ozone. CF2Cl2 + UV > CF2Cl + Cl (chlorine radical) Cl + O3 + UV > O2 + ClO ClO + O > O2 + Cl ( 1 Cl radical can destroy a hundred thousands of ozone) Practice test:à answer keyChapter 6 ââ¬â Thermochemistry * Nature of Energy * System versus Surroundings System ââ¬â the part of the universe we want to focus on (like a chemical reaction inside a beaker) Surrounding ââ¬â everything else in the universe (like the glass of the beaker and the air around it) * Definition of Energy, internal energy, law of conservation of energy Energy is classified into two types: a. heat (q) ââ¬â energy transferred that causes a temperature change (due to a change in the random motion of molecules) b. work (w) ââ¬â energy transferred that causes an object to move (due to a change in the concerted motion of the molecules in the object) c. nits of energy: I. Joule (J) ââ¬â the amount of energy it take to move 1kg mass a distance of 1 meter (unit: kg*m2/s2) II. Calorie (cal) ââ¬â the amount of energy needed to raise the temperature of 1 gram of water by 1 ? C 1 kcal = 1000 cal (food calories) 1 cal = 4. 184 J (exact measureme nt) Internal Energy ââ¬â total energy of a system. (Esystem) Law of conservation of energy ââ¬â energy is neither created or destroyed, only transferred. * 1st Law of Thermodynamics ââ¬â The change in energy of a system is equal to heat that enters the system plus the work done on the system. * ? E = q + w a. ?E = change in the internal energy of a system E is (+) if the energy is absorbed by the system ?E is (-) if the energy is released by the system b. q = heat q is (+) if the heat is absorbed by the system q is (-) if the heat is released by the system c. w = work w is (+) if the work is done on the system w is (-) if the work is done by the system on the surrounding * Heat and work * pV work ââ¬â is defined by the equation: w = -p? V * m Cs ? T heat transfer ââ¬â q = m Cs ? T where: m = mass Cs = specific heat capacity (J/ g ? C) ?T = (Tfinal ââ¬â Tinitial) ââ¬â q = n Cm ? T where: n = number of moles Cm = molar heat capacity (J/ mol ? C) ?T = (Tfina l ââ¬â Tinitial) conservation of thermal energy ââ¬â the amount of energy that is given must be equal with opposite sign to that energy that is being taken. qsurr = ââ¬â (qsys) msurr Cs(surr) ? T(surr) = -[msys Cs(sys) ? Tsys] * Calorimetry * Constant volume calorimetry * Constant volume calorimetry ââ¬â ââ¬Å"bombâ⬠calorimetry, no pv work done, therefore only heat contributes to ? E qcal = Ccal ? T = -qrxn where: Ccal = calorimeter constant (KJ/ ? C) * * only heat contributes to ? E * Enthalpy * Definition, equation Enthalpy (? H) ââ¬â the heat absorbed or released during a process taking place at a constant external pressure. ?H = qrxn = -qsurr ?H = -( m Cs ? T) Calculation using constant pressure calorimetry ââ¬â refer to example in notes * Exothermic versus Endothermic reactions (sign of ? H) Endothermic reactions have (+) ? H because they are reactions that absorb heat. Exothermic reactions have (-) ? H because they are reactions that give off hea t. * Hess's Law * Enthalpy of reactions manipulations 2 rules to remember: 1. If a reaction is reversed, the sign of ? H flips (from negative to positive or from positive to negative) 2. If you multiply coefficients by a number, ? H is also multiplied by that number. * This is a hard topic, please, please, please review this after Wednesday!
Monday, January 6, 2020
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