Water 2 - Properties of Water

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Presentation Description

A look at the chemical and physical properties of water and why it is so useful.

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Presentation Transcript

Properties of Water: 

Chemical, Physical, and Economic Properties of Water

Objectives: 

Objectives The student should have a broad overview of what makes water special chemically. The student should be able to list and explain various chemical and physical properties of water based upon its molecular structure. The student should understand how water impacts our economy and effects daily life.

Water: A Physical Description: 

Water: A Physical Description Water, at room temperature and 1 atm. of pressure, is a transparent liquid. Water freezes into a solid (ice) at 0 o C or 32 o F. Water boils into a vapor at 100 o C or 212 o F. Water has a density of 1 gram/milliliter at 4 o C. Water is composed of 2 Hydrogen and 1 Oxygen molecules. The angle formed is 105 o .

Water: A Chemical Description: 

Water: A Chemical Description Water is a polar solvent. The Oxygen atom provides an area of relative negative charge while the Hydrogen atoms provide an area of relative positive charge. The water molecule acts like a tiny magnet. It is attracted to other molecules of its own kind. The attraction of one water molecule to another gives water a strong surface tension. This means it has a high boiling point for a liquid of its molecular weight. Alcohol, by comparison, has a much higher molecular weight, but since it is non-polar, it boils at a much lower temperature.

Unique or Unusual Properties: 

Unique or Unusual Properties Water in its solid form is less dense that water as a liquid. Fish can live in cold climates because the ice on a lake will not sink to the bottom and crush them into the mud. For most substances, if a solid sample is placed in a liquid sample, the solid sinks. It is possible for water to exist as ice, steam, and liquid at the same time. If a temperature of exactly 273.16 K (0.01 °C) and a partial vapor pressure of 611.73 pascals (ca. 6.1173 millibars, 0.0060373057 atm) can be maintained, then water will remain stable at any of its three forms.

Universal Solvent: 

Universal Solvent Water is an excellent solvent. It will dissolve most things over time. Water is polar. It has a positive and negative area. Polar solutes like salt are easily dissolved. Water is also a small molecule. Many non-polar solutes, like sugar, will also dissolve in water, albeit they require more effort.

Economic Impact of Water: 

Economic Impact of Water Negative: Water, in great quantities can be a bad thing. Floods account for more deaths and lost property each year than any other type of natural disaster. The most common cause of death in a desert location, by natural causes, is drowning. WHY?

Economic Impact of Water: 

Economic Impact of Water Water positively impacts every aspect of our lives. We need it to drink, cook, clean, manufacture, feed our selves, generate power, or almost any action you can think of. Water is a vital substance for the human body. If we don’t get enough from food and drink we die in a matter of days. Water provides a habitat for a large portion of life on Earth. Everything from the smallest bacteria to the largest of whales, lives in water.

Clean Water: 

Clean Water Clean water is necessary for life. Contaminated water will not support life. Most life will not survive in salt water.