Water molecules have what kind of covalent bond and why?
water molecules are polar due to the unequal sharing of electrons, making a water molecule's overall charge unequal The oxygen atom in the water molecule is more electronegative than the hydrogens bonded to it, thus pull the electrons closer to it.
One water molecule can bond with how many water molecules and what are the intermolecular forces and intramolecular forces within a water molecule
- intermolecular forces: hydrogen bonds
- intramolecular forces: polar covalent
what are the four emergent properties of water that contribute to Earth's sustainability for life
- Cohesion & adhesion
- Moderation of Temperature (buffer)
- Ice floats
- Universal Solvent
what are the differences between cohesion and adhesion and why does it occur?
- cohesion: caused by the H-bonding between other molecules, it allows water to go against gravity as water molecules pulls other water molecules upward and holds them together. Also contributes to surface tension
- adhesion: also caused by H-bonding of water molecules but difference from adhesion is that water moelcules are attracted to other substances not water molecules.
how does cohesion and adhesion contribute to the sustainability of life?
- adhesion of of water molecules helps it resist the downward pull of gravity, allowing water to move upward within cell walls such as the stem of flowers
- cohesion of water molecules prevents water molecules from breaking apart as it moves upward within cell walls
Explain how water serves as a buffer
- Because water has a relatively higher specific heat than other substances, the temperature of water will not fluctuate tremendously
Why does water's high specific heat contribute to the sustainability of life?
- Because of it's high specific heat, water moderates temperature. It's effect is evident particularly in areas located in large bodies of water.
- Oceans moderate the temperature within the surrounding area, making coastal climates moderately cooler and permit life within Earth's oceans.
- Organisms are primarily made of water, thus they are better able to resist changes in their own temperature than other liquids with a lower specific heat.
- evaporative cooling: how sweat works as a cooling method is that the water molecules closer to the surface will most likely leave as gas and evaporate faster because it is relatively "hotter" than the water molecules below it. As a result, as liquid evaporates, the surface of the liquid remaining cools down.
How does ice float?
- As water freezes, the water molecules begin to solidify into a crystallized structure due to it's H-bonds. As a result, there is a created of more surface area and fewer water molecules than an equal volume of liquid water making ice less dense than it's liquid counterpart.
- Ice is 10% less dense and has 10% fewer molecules than liquid water
how is water a the best solvent?
- Because of a water molecule's polarity, water can dissolve any other polar substances.
- When a solute (substance being dissolved) is placed within water (solvent, substance doing the dissolving) water molecules surround each dissolved ions called a hydration shell