Presentation on theme: "By:Tyree Shavers. The Scottish chemist Daniel Rutherford (1749-1819). Rutherford kept a mouse in a confined quantity of air till it died. He then burned."— Presentation transcript:
The Scottish chemist Daniel Rutherford (1749-1819). Rutherford kept a mouse in a confined quantity of air till it died. He then burned a candle in what was left until the candle went out. He then burned phosphorus in what was left after that, until the phosphorus would no longer burn. Next, the air was passed through a solution that had the ability to absorb carbon dioxide. The air remaining now would not support combustion; a mouse would not live in it and a candle would not burn. Rutherford reported this experiment in 1772. Since Rutherford and Black were both convinced of the validity of the phlogiston theory, they tried to explain their results in terms of this theory. As mice breathed and as candles and phosphorus burned, phlogiston was given off and entered the air, along with the carbon dioxide that was formed. When the carbon dioxide was later absorbed, the air left behind still contained much phlogiston. In fact, it contained so much phlogiston as to be saturated with it; it would accept no more. That was why objects no longer burned in it. On this reasoning Rutherford called the gas he had isolated "phlogisticated air". Nowadays, we call it nitrogen, and give Rutherford the credit for its discovery.
Nitrogen makes up 78 percent of the earth's atmosphere and is essential to healthy plant growth. Without it, green plants are weak and smaller than they should be. Too much nitrogen, on the other hand, makes plants unable to withstand frosts or heavy winds. While many chemical fertilizers contain nitrogen, there are also natural sources of the element that do not put the environment at as much risk for pollution.
Nitrogen Physical Properties It is a relatively inert gas. It is colorless, odorless and tasteless. Liquid nitrogen is also colorless and odorless, and is similar in appearance to water. There are two allotropic forms of solid nitrogen, a and b, with a transition between the two forms at -237° C. Density : 1.25*10-3 g.cm-3 at 20°C Melting point : -210 °C Boiling point : -195.8 °C
Nitrogen Chemical Properties Nitrogen form compounds through biological activity, at high temperature, or at moderate temperature with the aid of catalysts. It forms nitric oxide and nitrogen dioxide with oxygen, ammonia with hydrogen, and nitrogen sulfide with sulfur. At high temperatures it will combine with certain active metals, such as lithium, magnesium and titanium to form nitrides. It is non flammable and will not support combustion. Energy of first ionisation : 1402 kJ.mol -1 Energy of second ionisation : 2856 kJ.mol -1 Energy of third ionisation : 4577 kJ.mol -1 Electronegativity according to Pauling : 3.0
Nitrogen ( is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. Many industrially important compounds, such as ammonia, organic nitrates (propellants and explosives), and, contain nitrogen. The extremely strong bond in elemental nitrogen dominates nitrogen chemistry, causing difficulty for both organisms and industry in breaking the bond to convert the N 2 into useful compound, but releasing large amounts of often useful energy, when these compounds burn, explode, or decay back into nitrogen gas.
Nitrogen is odorless, tasteless, and colorless. Nitrogen gas (N 2 ) makes up 78.1% of the volume of the Earth's air. Nitrogen is a nonmetal. Nitrogen gas is relatively inert, but soil bacteria can 'fix' nitrogen into a form that plants and animals can use to make amino acids and proteins. The French chemist Antoine Laurent Lavoisier named nitrogen azote, meaning without life. Nitrogen was sometimes referred to as 'burnt' or 'dephlogisticated' air, since air that no longer contains oxygen is almost all nitrogen. The other gases in air are present in much lower concentrations. Nitrogen compounds are found in foods, fertilizers, poisons, and explosives. Your body is 3% nitrogen by weight. Nitrogen is responsible for the orange-red, blue-green, blue-violet, and deep violet colors of the aurora. One way to prepare nitrogen gas is by liquefaction and fractional distillation from the atmosphere. Nitrogen has a valence of 3 or 5.