Реферат по предмету "Иностранный язык"


Nitrogen Essay Research Paper Nitrogen was isolated

Nitrogen Essay, Research Paper

Nitrogen was isolated by the British physician

Daniel Rutherford in 1772 and recognized as an

elemental gas by the French chemist Antoine

Laurent Lavoisier about 1776. Properties

Nitrogen is a colorless, odorless, tasteless,

nontoxic gas. It can be condensed into a colorless

liquid, which can in turn be compressed into a

colorless, crystalline solid. Nitrogen exists in two

natural forms of isotopes, and four radioactive

isotopes have been artificially prepared. Nitrogen

melts at -210.01° C (-346.02° F), boils at

-195.79° C (-320.42° F), and has a density of

1.251 g/liter at 0° C (32° F). The atomic weight of

nitrogen is 14.007. Nitrogen is obtained from the

atmosphere by passing air over heated copper or

iron. The oxygen is removed from the air, leaving

nitrogen mixed with some inert gases. Pure

nitrogen is obtained by partial evaporation of liquid

air because liquid nitrogen has a lower boiling

point than liquid oxygen, the nitrogen evaporates

off first and can be collected. Nitrogen composes

about four-fifths (78.03 percent) by volume of the

atmosphere. Nitrogen is inert and serves as a

diluent for oxygen in burning and respiration

processes. It is an important element in plant

nutrition certain bacteria in the soil convert

nitrogen from the atmosphere into a form, such as

nitrate, that can be absorbed by plants, a process

called nitrogen fixation. Nitrogen in the form of

protein is an important component of animal tissue.

The element occurs in the combined state in

minerals, of which saltpeter (KNO3) and Chile

saltpeter (NaNO3) are highly important products.

Nitrogen combines with other elements only at

very high temperatures or pressures. It is

converted to an active form by passing through an

electric discharge at low pressure. The nitrogen

produced is very active, combining with alkali

metals to form azides with the vapor of zinc,

mercury cadmium, and arsenic to form nitrides and

with many hydrocarbons to form nitriles. Activated

nitrogen returns to ordinary nitrogen in about one

minute.In the combined state nitrogen takes has

many reactions it forms so many compounds that a

systematic scheme of compounds containing

nitrogen in place of oxygen was created by the

American chemist Edward Franklin. In

compounds nitrogen exists in all the combination

capacity states between -3 and +5. Ammonia, and

hydroxylamine represent compounds in which the

combination capacity of nitrogen is -3, -2, and -1,

individually. Oxides of nitrogen represent nitrogen

in all the positive combination capacity states.

Uses Most of the nitrogen used in the chemical

industry is obtained by the fractional distillation of

liquid air. It is then used to synthesize ammonia.

From ammonia produced in this manner, a wide

variety of important chemical products are

prepared, including fertilizers, nitric acid, urea,

hydrazine, and amines. In addition, an ammonia

compound is used in the preparation of nitrous

oxide (N2O) a colorless gas popularly known as

laughing gas. Mixed with oxygen, nitrous oxide is

used as an anesthetic for some types of

surgery.Used as a coolant, liquid nitrogen has

found widespread application in the field of

cryogenics. With the recent advent of ceramic

materials that become superconductive at the

boiling point of nitrogen, the use of nitrogen as a

coolant is increasing.




Не сдавайте скачаную работу преподавателю!
Данный реферат Вы можете использовать для подготовки курсовых проектов.

Поделись с друзьями, за репост + 100 мильонов к студенческой карме :

Пишем реферат самостоятельно:
! Как писать рефераты
Практические рекомендации по написанию студенческих рефератов.
! План реферата Краткий список разделов, отражающий структура и порядок работы над будующим рефератом.
! Введение реферата Вводная часть работы, в которой отражается цель и обозначается список задач.
! Заключение реферата В заключении подводятся итоги, описывается была ли достигнута поставленная цель, каковы результаты.
! Оформление рефератов Методические рекомендации по грамотному оформлению работы по ГОСТ.

Читайте также:
Виды рефератов Какими бывают рефераты по своему назначению и структуре.

Сейчас смотрят :

Реферат Религия и ее роль в культуре Русская реалистическая литература XIX ве
Реферат Шпаргалки по теории государства и права (100 вопросов)
Реферат 1. 3 Difficulties which pupils have in reading in the English language…
Реферат Россия в эпоху Петра I (1682-1725 гг.)
Реферат 1 место: Корж Ирина, 662978, г. Железногорск, кгооу «Железногорская санаторно-лесная школа» 2 место
Реферат Экономический рост 6
Реферат Дети как объект рекламного воздействия
Реферат Благотворительность как основа социальной работы
Реферат Romantic Virtuosity Essay Research Paper Romantic VirtuosityMusic
Реферат Пула - город Истрии
Реферат Организация кредитования физических лиц в Северо-Западном банке Сбербанка России
Реферат Судебная экспертиза в уголовном процессе
Реферат Особенности профессионального общения в деятельности юриста
Реферат Языковые особенности дилогии П.И. Мельникова "В лесах" и "На горах"
Реферат Проблемы государственной службы и правовой механизм их регулирования по материалам управления государственной и муниципальной службы Московской области