Essay Ch1 Flashcards
Importance of cohesion and adhesion
This (cohesion) contributes to the transport of water and dissolved nutrients against gravity in plants. The adhesion allows water to stick to the cell walls, through hydrogen bonding, which helps counter the downward pull of gravity.
Water is cohesive and adhesive
Cohesive means that water molecules stuck to each other due to the hydrogen bonds.
Adhesion, or clinging of one substance to another.
High specific heat
Specific heat is the amount of heat that must be absorbed to raise 1 gram of water 1 degrees Celsius. Water has a high specific heat meaning that a large amount of energy must be used to raise the temperature. This is due to the hydrogen bonds of the molecule.
Describe bonds in high specific heat
The bonds break and reform constantly and in order for the bonds I break, heat must be absorbed. When the bonds form however heat is released and when the temperature decreases even slightly, more bonds form.
Importance of high specific heat
Waters high specific heat enables earth to be habitable, since it keeps the temperature on land and in water within the limits that permit life.
High heat of vaporization
The heat of vaporization is the amount of energy it takes to convert 1 gram of water to a vapor or gaseous state. Again, water has a high heat of vaporization because of the hydrogen bonds.
Explain bonds for high heat of vaporization
The constantly fluctuating hydrogen bonds make it hard for the water molecules to be separated enough to change phase from liquid to gas.
Importance of high heat of vaporization
On Earth, this plays a role in evaporative cooling which helps moderate the Earth’s climate and prevents organisms from overheating.
Water expands when it freezes and becomes less dense.
When water transforms into a solid, the hydrogens form the maximum number of bonds. Since these bonds spread out, a greater amount of space is used, therefore causing the solid to be expanded and also less dense than it would be in liquid form.
Importance of water expanding and less dense
This is essential to living organisms because if ice sank, life on Earth would not be possible. Entire bodies of water would freeze, preventing life; in the summer, only a small proportion of the frozen bodies of water would thaw.
Water is a versatile solvent
Meaning that it is able to dissolve a large amount of substances- ionic and polar covalent compounds. This is owed to water’s polarity. The oxygen atom is partial negative and the two hydrogen atoms are partial positive.
Expand on polarity for solvent
These isolate the ions in ionic compounds and surround them with a hydration shell, working until the entire substance is dissolved. For polar covalent compounds, hydrogen bonds form when the water molecules form around the solute particles, causing them to dissolve
Importance of versatile solvent
This is demonstrated in biological fluids such as blood, plant sap, and liquids within cells
