Yi Kuishuai 2P2 31 5/2/11

Ammonia (NH₃)

Made from: Nitrogen, Hydrogen.

Chemical bonding: Covalent bonding

Harmful effects: It can burn skin. Inhaling Ammonia can cause fainting, or even death. It can bleach to form dangerous gases such as chloramines. It can dissolve many things.

Constituent elements:

Nitrogen:

Nitrogen is the most abundant gas in our atmosphere (78%). It is found in group V and it has valence electrons of 5. It appears in our atmosphere in the form of Nitrogen gas, as it is not stable because it only has 5 valence electrons. It is colourless, tasteless and odorless. Nitrogen has 4 isotopes. They are ¹³N, ¹⁴N, ¹⁵N, and ¹⁶N. It is used in the packaging of food. Liquid nitrogen is used to cool substances, especially machines in factories. However, skin contact with nitrogen could cause severe frostbite and maybe death. Nitrogen had so strong covalent bonds that people call it “nitrogen diamond”! Nitrogen is vital for plants to grow well and it is considered a nutrient. As a result, it is often used as fertilizers for plants. Nitrogen is also crucial to all life, as it is a component of all the proteins in living things. The most commercial compound of nitrogen is ammonia. Nitrogen is also found in a variety of food, explosives, poison, acids. So, nitrogen is an important element in our world!

Hydrogen:

Hydrogen is the first and simplest element in the periodic table. It is the only element which does not have a neutron and is the only element that can exist without neutrons. Hydrogen has 3 isotopes and some isotopes contains neutrons. It is highly flammable. It is essential for life as it is found in many amino acids in proteins. It also burns with oxygen to form water (H₂O) which is also an important factor for life. It is the lightest gas in the world. It is used in rocket fuels as it is highly flammable and it “explodes” when it burns with oxygen. It rarely reacts with substances unless burned. Hydrogen has an almost invisible flame that could cause accidental burns. It is the most abundant element in the whole universe! Over 90% of the Universe’s atoms is hydrogen atoms! Some cars in the world are powered by hydrogen. In the engine, hydrogen would react with oxygen to form water and at the same time, produce energy. This is a very “green” way to save the earth as the car would only emit out water! So, hydrogen is an important element in our world and may become more  important in the future!

Formation:

An Ammonia molecule is formed when a nitrogen atom reacts with 3 hydrogen atoms. Nitrogen has valence electrons of 5 while hydrogen has valence eletrons of 1. Thus they bound together easily because they would form 8 valence electrons together. It requires high temperatures (400^oC) and high pressure (150-250 bar) to react.Ammonia is mostly produced in factories.  It is formed when a nitrogen gas compound (N₂) reacts with 3 hydrogen gas compounds (3H₂) to form 2 ammonia compounds (2NH₃). During formation, one of each valence electron of nitrogen and one electron of hydrogen combine and form a single covalent bond. Similarly three bonds are formed between the Nitrogen atom and three Hydrogen atoms respectively. In each of these three covalent bonds formed between Nitrogen and Hydrogen, one electron is provided by Nitrogen and one electron is provided by the Hydrogen atom.

Dot and Cross Diagram: