Tuesday, August 23, 2011

AP Biology post 2

Discuss the four emergent properties of water that contribute to Earth's fitness for life.

8 comments:

  1. 1. its cohesive which means molecules can come together to form a body of H2O. it is also adhesive and can stick to other objects. (ex - going up a trees roots to hydrate the leaves)
    2. it can withstand moderate temperatures because it is has hydrogen bonding which makes it more difficult to calculate rather than having a low evaporation temperature. (ex - swimming pool)
    3. it can expand instead of breaking when it is frozen at low temperatures and it can float on water when it is ice. (ex - glaciers)
    4. it is a versatile solvent which means most this that are put in water can dissolve relatively easily. (ex - dissolving sugar)
    :^)

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  2. Because water is a polar molecule (slightly charged molecule), it can be attracted to itself and form hydrogen bonds between themselves. This gives water its cohesive and adhesive abilities, and gives water it's four emergent properties.

    1. Water's ability to moderate temperature comes from the many hydrogen bonds in water. More heat is needed to be absorbed or released to break or make those bonds. (ex. coastline cities are cooler than those away from the ocean)

    2. Water is less dense in solid from then in liquid form. Water molecules are precisely arranged due to hydrogen bonds, which make them expand and decreases their density. This causes ice to float. (If ice would sink in water, then they would never melt from the sun's heat, and the sunken ice would eventually accumulate and freeze most of Earth's water.)

    3. Water is a versatile solvent. It's actually the universal solvent because many substances can be dissolved in water. This happens because water's slightly charged ends attract to ionic and slightly charged molecules (adhesion), and forms a hydration shell around it. (ex. salt dissolved in water)

    4. Water's high surface tension also has to do with the hydrogen bonds found in it that gives it its cohesive ability. Water molecules stick to each other to give water a boundary or skin. Because the hydrogen bonds aren't as strong as other bonds, water's surface tension can be easily broken, but still strong enough to keep bugs and leaves afloat.

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  3. The four emergent properties of water are:

    1. Cohesive behavior- In a sample of liquid water, many of the molecules are bonded together by hydrogen bonds. These bonds give water a more discrete structure than other liquids. The hydrogen bonds en masse hold the liquid together.

    2. Ability to moderate temperature- Water absorbs heat from air, stores it, and releases it in areas of cooler air. This ability to store temperature also changes very little in the actual temperature of the water.

    3. Expansion upon freezing- Hydrogen bonding causes water to expand as it solidifies, while most other liquids contract. When water freezes at 0 degress Celcius, water molecules bind to four other partners respectively and separate, forming a crystalline lattice.

    4. Versatility as a solvent- Water can dissolve many substances because of the polarity of its molecules. Since the oxygen region of the water molecule is negatively charged, and the hydrogen regions are positively charged, ions can have an affintiy with them. However, compounds do not necessarily need to be ionic to dissolve in water. Compounds made of polar molecules dissolve when water molecules surround them and form hydrogen bonds with them (E.g- Sugar.)

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  4. The four emergent properties of water are:
    1. Cohesive Behavior: Water has a behavior unlike any other where it can pull other water molecules against gravity using its hydrogen bonds.

    2. Moderation of Temperature: Water can moderate air temperature by absorbing heat from air that is warmer and releasing the stored heat into the cooler air. Water can absorb or release heat with only slightly changing its own temperature.

    3. Expansion upon Freezing: When water begins to freeze at 0 degrees Celsius, the hydrogen bonds allow the water to expand. Water molecules begin to bind to four other molecules and separate.

    4. Versatility as a Solvent:Water can dissolve many different substances due to the polarity of its molecules.

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  5. Cohesive behavior: Water molecules bond to each other with hydrogen bonds, which gives it a high surface tension and enables insects to walk on water.

    Moderation of temperature: Water absorbs heat when hydrogen bonds are broken, and heat is released when hydrogen bonds are formed. It has a high heat capacity. This gives water a high heat of vaporization.

    Expansion upon freezing: Because this happens, ice is less dense than water, causing it to float. If ice did not float in water, it would not melt and eventually all bodies of water would be iced, and life on earth would not be possible.

    Versatility as a solvent: Water could dissolve ions and polar molecules because of its polarity, making it the most versatile known solvent.

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  6. Water has four emergent properties cohesion, expansion among freezing, versatility as a solvent and ability to moderate temperature.

    1. Cohesion- the cohesive behavior of water allows itself to bind with other water molecules with hydrogen binding. For example because of water's cohesive behavior water can travel up the roots of plants to the leaves(go against gravity)

    2. Expansion among freezing- water freezes at 0 degrees Celsius; however, it is most dense at 4 degrees Celsius. At 4 degrees Celsius the water molecules are "arm's length" apart making it a hard substance to break or damage. Ice also floats which is very important. if ice were to sink all oceans, lakes, river, etc would freeze and earth would be inhabitable.

    3. Versatility as a Solvent- Many substances dissolve in water because water molecules are polar. since the molecules are polar they have slight charges. these charges attract ionic or other molecules. Thus, the water molecules "cover up" the substance and form hydrogen bonds. (example- sugar and salt dissolve in water).

    4. Ability to moderate temperature- Water can absorb heat from the sun, store the heat and eventually release it into cooler temperatures. Also all this can occur with water barely changing its own temperature.This is why the coastal areas are always cooler than the inland areas.

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  7. Water is a very important compound in our lives.

    It has moderation of temperature which makes it difficult for it to gain or lose heat quickly. this causes a high heat capacity, and a high heat of vaporization.

    Water expands upon freezing, this causes ice to be less dense than the liquid form, water, which allows ice to float on water.

    water is know as the universal solvent, because of its ability to disolve many substances. this is ccaused from its polar covalernt bond between oxygen and hydrogen.

    water has cohesive and adhesive behavior, meaning it can bind to itself and others giving it a high surface tension.

    Water can thank its ability to hydrogen bond with other water molecules for its emergent properties that are necessary for life

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  8. 1. Cohesive behavior: the binding together of like molecules, often by hydrogen bonds.
    2. Ability to moderate temperature: (high heat capacity)water moderates air temperature by absorbing heat from air that is warmer and releasing the stored heat to air that is cooler.
    3. Expansion upon freezing: when water freezes it expands and becomes less dense than its liquid form, allowing it to float.
    4.Versatility as a solvent: water is a very versatile solvent, a quality we can trace to the polarity of the molecule

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