TR3.5

Water with Paul

Houjun Liu 2021-09-27 Mon 12:00

1 Alright, let's talk about water.

Screen Shot 2020-08-24 at 10.08.34 PM.png

Figure 1: Watah!

1.1 Intra-Molecular water bonds

  • As we know (or looked up from the PTable)
  • Hydrogen has electronegativity of 2.20, and oxygen has EN 3.44
  • The difference >0.4 <1.7 makes these bonds polar covalent

See KBhBIO101BondingReview, bonding review

Test

1.2 Why is ice less dense?

  • Freezing usually bring new ordering of molecules to make it paced
  • But! Not the case for normal water because of hydrogen bond
    • Strong 6-ring Hydrogen bonds in ice prevents shrinking
    • Empty space filled with air, making it less dense

1.2.1 Why do I care?

Ice floats! Causing beautiful ice effects that the ecosystem uses

  • Pseudo-landmass
    • Antarctica
    • Animal habitat
  • Ice reflect incoming light ("albeto")
    • Bounces energy off
    • Cools the water

1.3 Inter-Molecular water bonds properties

See KBhBIO101PropsOfWater, properties of water.

2 So, why is water the chosen liquid?

See also KBhBIO101PropsOfWater Properties of Water

  • Liquid at Earth temperatures
  • Sticky => strong bonds that help water hold together + resist change in temperature (hence why AlcaholLand cannot exist).
    • Varing te (incomplete #todo-houjun @jemoka)
  • Is universal solvent