High School Students’ Conceptions about Energy in Chemical Reactions (focusing only in exothermic and endothermic reactions). Aim The aim of this study is to investigate students’ understanding of the energy concept in chemical reactions particularly in endothermic-exothermic reactions. Both qualitative and quantitative methodology was used for this investigation. A twenty-item multiple choice test was developed about the topic to measure the students’ understandings. This concept test was
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Chapter 1 Chemical Reactions and Equations Q.1. Why should magnesium ribbon be cleaned before burning in air ? Ans: Magnesium ribbon is a very reactive metal. When stored it reacts with oxygen to form a layer of magnesium oxide on its surface. This layer of magnesium oxide being a stable compound prevents further reaction of magnesium with oxygen. The magnesium is cleaned before burning in air to remove this layer so that the metal can be exposed to air properly. Q.2. Write the balanced
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metals arranged in order of their reactivity based on displacement reactions‚ reduction of their oxides by hydrogen or carbon‚ the relative ease of decomposition of their compounds and reactions with oxygen‚ dilute acids and water. The higher up a metal is in the reactivity series‚ the more reactive it is. In the experiment conducted‚ the three metals‚ magnesium‚ zinc and copper each had to undergo displacement reactions and reactions with water‚ oxygen and dilute acids‚ to arrange them in the order
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Title Experiment 17 Reaction Kinetics- Determination of the Activation Energy of the Reaction Between Oxalic Acid and Potassium Permanganate. Objective To determine the activation energy of the reaction between oxalic acid and potassium permanganate. Theory and Background Activation energy is the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation or physical transport. In terms of the transition-state
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Coupled Reactions Louella Rose E. Tan‚ Frances May L. Coralde Institute of Chemistry‚ University of the Philippines‚ Diliman‚ Quezon City 1101 Philippines Results and Discussion A combustion reaction is a reaction that liberates heat and light. Magnesium is a stable element and reacts violently with evolution of much heat and light. The reason the magnesium burned in carbon dioxide was because it combined with the oxygen in the CO2 leaving elemental carbon behind. CO2(g) C(S) + O2(g)
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Redox reactions (Redox terminology‚ galvanic cells‚ standard electrode potentials‚ strength of oxidizing/reducing agents‚ corrosion and protection against it) Oxidation is defined as the loss of electrons and reduction is defined as the gain of electrons. Oxidizing agents‚ such as oxygen are defined as substances which accept electrons; reducing agents are substances which donate electrons. Redox reactions are: a) The reactions of metals with non-metals 2Na+Cl2→2Na+Cl- b) The reactions
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family. Two examples of this would be a memoir‚ Night‚ by Elie Wiesel and a movie‚ Life is Beautiful directed by Roberto Benigni. While some similarities are noticeable‚ the differences are astonishing and striking‚ which gives the audience various experiences. One point of similarities and differences would be the characters and the relationships that the characters have in both stories‚ Night and Life is Beautiful. For example‚ there is a father-son relationship in each of the stories. In Night‚ the
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Schindler’s List and Life is Beautiful The films Schindler’s List and Life is Beautiful both have aspects that can be comparable and contrasted. Both films are on Holocaust dramas and that took place. The films brings out the horror at the Nazi concentration camps. In addition‚ the films shows the dictatorship and evil of racism. What is more‚ both the films show heroism at overpowering despair. They show how the human spirit can struggle against any oppression. The Schindler’s List is on a
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REACTIONS OF HYDROCARBONS Vanessa P. Manibpel De La Salle University - Dasmariñas ABSTRACT Five substances namely Hexane‚ Eugenol‚ Unknown hydrocarbon 1‚ Unknown hydrocarbon 2‚ and Acetylene gas was used for the selective reactivity of hydrocarbons to functional group tests; Bayer’s test‚ Bromine test light‚ Bromine test dark‚ and Tollen’s test. In Bayer’s test‚ only Acetylene‚ Eugenol and Unknown hydrocarbon 2 reacted positively and the rest retain the purplish color of KMnO4. On the other hand
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Kristi Moos Eng 104 27‚ October 2014 EID In Muslim culture EID is one of the important festivals in a year. Each year EID comes twice‚ one is Eid-al-Fitr and second is Eid-al-Adha. These two mean different things like Eid-al-Fitr is the first one when the end of the month of Ramadan‚ which is the month in which Muslims fast every day from sunrise to sunset. The entire community comes together for special prayers and to congratulate each other. And the second one is Eid-al-Adhais the second and final
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