Chapter 3 water and life essay Flashcards
What to discuss in what order
- waters polarity
2. four properties of water
What do covalent bonds in water molecules result in
hydrogen bonding
How is water polar
electrons spend more time near oxygen then hydrogen
What does polarity allow a water molcule to do
make hydrogen bonds with one another
Four emergent properties of water
- Cohesion
- Temperature moderation
- Expansion upon freezing
- Versatility as a solvent
Parts of cohesion
Cohsion: hydrogen bonds hold water molecules together
Adhesion: an attraction between substances (ex: plant cell and water)
Surfce tension: the measure of how hard it is to break the surface of a liquid (EX: spider can crawl on water)
Temperature moderation components
Temperature moderation: water absorbs heat in warm weather and releases it in cool weather
High specific heat: How much heat is needed to heat up one gram of water to change its temperature by one degrees celsius. Can be traced to hydrogen bonding, heat is absorbed when hydrogen bonds break and released when they form
Resistance to major temperature change: due to high specific heat, water stops temperature from flucuating too much
Heat of vaporization: amount of heat required to turn 1g of water into a gas
Evaporative cooling: surface of water cools during evaporation. Helps stabilize temperatures in organisms and in bodies of water
Expanision upon freezing
hydrogen bonds become more ordered when water is frozen. water becomes less dense. It allows ice to float. If this didnt happen, ice would sink and all water would eventually freeze over
Versitality as a solvent
A solvent is what dissolves a solute
Almost a universal solvent, cannot dissolve lipids and large hydrocarbons because thehy are nonpolar
Waters polarity allows it to be a versitile solvent (allows it to form hydrogen bonds easily)
