Hypoglycemia,pregnancy Causes

IMPORTANCE OF WATER .- Life as we know it depends on water, which is the most abundant substance in the tissues of plants and animals, as well as most of the land surface.

exceptional properties of water have great effect on the nature of our environment. Its high specific heat helps prevent large temperature fluctuations in the Earth's surface. The water masses of the oceans and lakes absorb heat from the sun during the day and release it into the atmosphere during the night without experiencing a significant temperature change. The lunar surface has a specific heat which is the fifth of the water and thus subjected to variations in temperature between 120 ° C and -150 ° C.

The fact that water expands when it freezes beneficial and harmful effects. It damages the tissues of animals and plants and causing cells to rupture. The same process causes the breakdown of rock materials to produce fertile soil.

The lower density of solid water (ice) compared to that of liquid water leads to the ice to float and thereby prevents the water from the seas and lakes freeze completely and the disastrous consequences this would imply.

water properties change markedly when substances dissolve in it and these can be mixed with water naturally, as with the dissolved salts in seawater, and others that are introduced as a result of human activities, many times these impurities have a negative effect on water bodies and ways of life that need them.

Water is the main component of living matter. Constitutes 50 to 90% of the mass of living organisms. The protoplasm, which is the basic material of living cells in a solution consisting of fats, carbohydrates, proteins, salts and other similar chemicals in water. Water acts as a solvent carrying, combining, and chemically breaking down these substances. The blood of animals and plant sap contains a large amount of water, used to transport food and waste material disposal.

Water plays an important role en la descomposición metabólica de moléculas tan esenciales como las proteínas y los carbohidratos. Este proceso, llamado hidrólisis, se produce continuamente en las células vivas.

ESTRUCTURA MOLECULAR DEL AGUA .- Las propiedades físicas de las sustancias puras dependen de dos factores:

1. De la naturaleza de sus unidades estructurales (átomos, iones o moléculas).
2. De la intensidad de las fuerzas (interatómicas, interiónicas o intermoleculares) que existen entre sus unidades estructurales.
   

Para poder entender las propiedades del agua tenemos que conocer primero su estructura molecular.

Water is a molecular compound as its structural unit is the molecule of water formed by an oxygen atom bonded to two hydrogen atoms by polar covalent bonds, which determines an unequal distribution of electric charge between atoms oxygen and hydrogen. Oxygen-hydrogen bonds formed between an angle of 104.5 degrees or so.

The fact that the atom in water are linked by covalent bond polar and angular structure of it determined that its molecules are polar, ie they present a slightly positive pole and the other slightly negative.

The polar nature of the molecules gives rise to the existence of attractive forces between them and the establishment of hydrogen bond links between them. This force of attraction must add it to the force of attraction due to its mass.

PHYSICAL PROPERTIES OF WATER .- Among others are:

1. FITNESS .- Water in its natural state is liquid. If the forces of attraction between molecules depend only on their molecular masses (18 amu) the water should be in a gaseous state that would render life on earth as we know. The polarity of molecules significantly increases the force of attraction between them determine your fitness is liquid.
2. .- BOILING POINT 100 ° C. It This is abnormally high in relation to their molecular weight, however, due to the polarity of the molecules and consequent greater force of attraction between them, the boiling point is understandable.
3. DENSITY .- It is 1 g / cc, ie about one cubic centimeter of water weighs one gram.
4. .- OR SPECIFIC HEAT heat capacity of water is 1cal / g ° C, this means that to raise the temperature one gram of water one degree centigrade have to apply one calorie of energy. Its heat capacity is greater than any other liquid.
5. SOLVENT POWER .- Water is an excellent solvent so much so that it is known as the universal solvent. Since its molecules are polar, water is a polar solvent and therefore only dissolves polar substances.
6. WATER IONIZATION .- The water to be a molecular compound ionizes very little if we take one liter of ionized water only 10 -7 moles of the same (10 -7 mol / l) . Ionization occurs as suggested later.
   H 2 O -----> H + + OH-
7. .- Electrical conductivity of pure water is poor conductor of electrical current due to the small amount of free ions it contains. The electrical conductivity of water can be increased by dissolving in it any substance which increases the amount of free ions.
8. SOLIDIFICATION WATER .- When water becomes solid increases in volume due to the linear association of molecules of liquid water due to hydrogen bond links is modified resulting in another type of association leaves many gaps between the molecules, hence its mayor volumen. Esta forma de comportamiento determina que la densidad del agua sólida sea menor que la del agua líquida (aproximadamente 0,9g/cc), por esta razón el hielo flota.
9. ESTABILIDAD QUÍMICA DEL AGUA .- El agua es un compuesto que en estado líquido es muy estable debido a la gran estabilidad de los enlaces hidrógeno oxígeno. No se descompone fácilmente por acción del aumento de temperatura: a los 2 500°C solo se descompone el 2% de sus moléculas.

PROPIEDADES QUÍMICAS DEL AGUA .- Entre ellas tenemos:

1. Reacciona con algunos óxidos ácidos oxyacids forming.
2. Reacts with some basic oxides to form hydroxides.
3. reacts with certain metals (alkali metals) forming hydroxides and releasing hydrogen.
4. The water reacts with nonmetals, especially with halogens, eg: red coal By passing the water breaks down and forms a mixture of carbon monoxide and hydrogen (water gas).
5. Some metals decompose cold water and others did at elevated temperature.
6. form complex combinations of water with some salts, which are called hydrates. In some cases hydrates lose water of crystallization changing appearance, and are said to efflorescence, as happens with cupric sulfate (CuSO4.5H2O), which when hydrated is blue, but water loss is transformed into cupric sulfate anhydrous white.
   

BUILDING LONG-TERM MEMORY (44 )

1. Consulting library books or the Internet, developed in your work file the following topics: * Lessons
   water: hard water, heavy water, distilled water.
   * Water supply .- Characteristics, clean water: stages.
2. Why water is a molecular compound?
3. Why water molecules are polar?
4. Why should the forces of attraction between molecules of water?
5. Why water is liquid?
6. If the forces of attraction between water molecules only their masses were due to its boiling point "would be higher or lower than 100 ° C? Why?
7. Suggest the meaning of the following expressions regarding the properties of water.
   D = 1g/cc; Ce = 1cal/goC; Degree of ionization = 10 -7 mol / l
8. What is the advantage of high specific heat of water?
9. What is the advantage of the less dense than water ice?
10. What is the benefit it gives us the fact that water increases in volume on freezing?
11. graphics with a sequence described as the water dissolves polar substance.
12. Why pure water is poor conductor of current and tap water good conductor of electricity?
13. cites 10 reasons why water is important.