BIOLK101 - Chemical Context of Life + Properties of Water

electron

negligible weight, equal to the # of protons when uncharged

What determines the reactivity of an atom?

electron

isotope

differs by amount of neutrons, changing the atomic mass

Hydrogen bonding

a bond with hydrogen and F,O, or N will be attracted to a different electronegative atom

4 properties of water

water sticks to itself

water expands on freezing

water has high specific heat

water is a good solvent

Cohesive

form hydrogen bonds with other elements

adhesion

form hydrogen bonds with other elements

capillary action

cohesion/adhesion where water “climbs up” a narrow space”

water expands on freezing

hydrogen bonds are together when frozen

liquid water

hydrogen bonds breaking and reforming

specific heat

the amount od energy it takes to change a liquid by 1 degree celsius

heat of vaporization

heat absorbed 1g of smth to be converted to gas

evaporative cooling

carries off heat to decrease temperature of something (sweat)

How does evaporative cooling work?

water from sweat absorbs heat off of skin and the energy of the remaining drops decrease and the temperature decreases

1M NaCl

58.44 g/L (1 mole)

1% NaCl

1 g in 100 mL (W/V)

Why is water a good solvent?

It’s polar (negative pole interacts with positive poles of solute)

Buffers

keep pH stable by donating/accepting H+ or OH-