Chemical composition of water

19,378 views 8 slides Oct 17, 2014
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Chemical Composition of Water

Water   is a transparent fluid which forms the world's streams, lakes, oceans and rain. Water is the   chemical substance   with   chemical formula   H2O: one   molecule   of water has two   hydrogen   atoms covalently   bonded   to a single oxygen   atom. Water appears in nature in all three common states of matter (solid, liquid, and gas).

Water is a liquid at   standard temperature and atmospheric pressure . Water has interesting thermal properties. When heated from 0°C, its melting point, to 4°C, it becomes more dense; most of the other substances become less dense when heated. Conversely, when water is cooled in this temperature range, it expands. It expands greatly as it freezes; as a consequence, ice is less dense than water and floats on it. Because of hydrogen bonding between water molecules, the latent heats of fusion and of evaporation and the heat capacity of water are all unusually high.

The intrinsic colour of water and ice is a very slight blue hue.

Since the water molecule is not linear and the oxygen atom has a higher electronegativity than hydrogen atoms, the oxygen atom carries a slight negative charge, whereas the hydrogen atoms are slightly positive.

Water facts :

1. Water is a good polar   solvent   and is often referred to as   the universal   solvent . 2. Other names for water are: dihydrogen monoxide, oxidane, hydroxylic acid, and hydrogen hydroxide. 3. Pure liquid water at room temperature is odorless and nearly colorless. Water has a faint blue color, which becomes more apparent in large volumes of water. 4. Water has the second highest specific heat capacity of all known substances. (Ammonia has the highest specific heat.) Water also has a high heat of vaporization . The high specific heat and heat of vaporization result from the high degree of hydrogen bonding between water molecules. One consequence of this is that water is not subject to rapid temperature fluctuations. On Earth, this helps to prevent dramatic climate changes.

Thanks for watching GROUP 3 Julia Brzozowska – Poland Anna Hermanowska – Poland Agata Panasiuk - Poland Hiurma Martín Cejas - Spain Alejandro Martínez González - Spain Marta Peña Díaz - Spain Pablo Rodríguez Hernández - Spain Jorge Victorian Gago - Spain Paula Acha Evora - Spain Alejandro Acosta león - Spain Kaan - Germany