Методическая разработка по английскому языку для студентов факультета химии и химической технологии " Simple Chemistry" Алматы 2017
Ex. 7 Read and translate the text
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мет. разработка по химии
| Ex. 7 Read and translate the text
Arrhenius theory Svante Arrhenius devised the first modern definition of acids and bases. An Arrhenius acid is a substance that dissociates in water to form hydrogen ions (H+); that is, an acid increases the concentration of H+ ions in an aqueous solution. This causes the protonation of water, or the creation of the hydronium (H3O+) ion. An Arrhenius base is a substance that dissociates in water to form hydroxide (OH−) ions; that is, a base increases the concentration of OH− ions in an aqueous solution. The Arrhenius definitions of acidity and alkalinity are restricted to aqueous solutions, and refer to the concentration of the solvent ions. Under this definition, pure H2SO4 and HCl which dissolve in toluene are not acidic and molten NaOH and solutions of calcium amide in liquid ammonia are not alkaline. The reaction of an acid with a base is called a neutralization reaction. The products of this reaction are a salt and water. Acid + base → salt + water In this traditional representation we formulate an acid-base neutralization reaction as a double-replacement reaction. For example, the reaction of hydrochloric acid, HCl, with sodium hydroxide, NaOH, solutions produces a solution of sodium chloride, NaCl, and some additional water molecules. HCl(aq) + NaOH(aq) → NaCl(aq) + H2O The modifier (aq) in this equation is important. It indicates that the substances dissolve in water. In fact though all three substances, HCl, NaOH and NaCl are capable of existing as pure compounds, in aqueous solutions they fully dissociate into the (aquated) ions H+, Cl-, Na+ and OH-. Vocabulary modern definition современное определение to devise разрабатывать An Arrhenius acid кислота Аррениуса to dissociate диссоциировать to increase увеличивать to cause вызвать protonation протонирование, присоединение протона creation создание that is поэтому An Arrhenius base основание Аррениуса acidity кислотность alkalinity щелочность to restrict to ограничивать to refer to относиться a solvent растворитель under this definition согласно этому определению toluene толуол molten расплавленный, жидкий calcium amide амид кальция neutralization нейтрализация a salt соль representation описание, представление double-replacement reaction реакция обменного разложения a liquid ammonia жидкий аммиак to formulate формулировать sodium hydroxide гидроксид натрия sodium chloride хлорид натрия important важный aquated гидратируемый to indicate указывать на though хотя жүктеу/скачать 422,31 Kb. Достарыңызбен бөлісу:
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