Module B Flashcards
what is imp with water chem
covalent bonds share
strong bonds so lots E needed to break tem
polarity from separation of charges = dipole molecule
cohesion = surface tension
can dissolve anything with enough time (ultimate solvent)
water thermally
high heat capacity
density and water
decreased in solid form (ice)
how solid material dissolved in water done
in parts per thousan %
through eletric conductivity
seawater
solution of salts in water
salts produce cations and anions in solution
amoutns vary but relative proportions over mills of yrs
driven b phys, che, and bio cycling of elements
non conservative
bio and chem reactive ions, nuts and gases
vertical and horz dsitribution show
conservative
ions and elements remain unreactive (inert)
stay in ocean longer than mixing time and so evenly distributed in time and space scales
distribution impacted by input and output of water
high surface tension
dipole attracted to other H bonds
linking neg ends to positive ends of another
weaker than covalent but strong enough
universal solvent
dipole allows
solutes of anion and cation form hydration shels
other polar compounds (dont seperate ions) positive side attracted to neg and vise versa
solid water less dense than liquid
thermal props = strong intermolecular H bonds
geo arrangment allows
max density is 3.98 C
ice forms, water below blocked from heat release
highest heat capacity of water
amount of heat required to increase temp of 1g by 1C
E stored in vibration within and btw molecules
vibration is T
salinity
total amount solid material dissolved in water (salt, other amts, gases)
fine material nad Organic comps NOT SALINITY
how to measure salinity
gravimetrically (weight) firtst
now chemically: measure one major constit by titration and calculate based on relative proportions
most common is phys: elctrical conductivty
pure water salinity
0%
open sea salinity
33-38% (avg=35%)
close to rivers salinity
0 - <35%
one of saltiest seas
dead sea
CHECK %
denser than humans so we float here
5 things in seawater
major constituents dissolved gases nutrients trace elements organic compounds
hydrological cycle
4 reservoirs : ocean, water vap in atm, water on land, solid ice
cycles btw ^^ on pathways = fluxes
(evap to water to rain ect)
salt removal
output from salt
ice, evap*, sea spray, chem precip, adsorption onto solids, deposition onto floor, accum of bio hard parst, reaction at hydrothermal vents
6 major ions
Cl- Na+ SO4 MG2+ Ca2+ K+
ions with large volcanic, hydrothermal vent sources
Ca2+, K+, SO4, CL-
- large input sources account for abundance in water
carbonate and silica in seawater
not abundant in seawater as in rivers
large bio sink remove them as delivered to seawater
CA2+ balances hydrothermal vents
Na+ and Cl- abundant in river, but as ffectively remoces
geochem cycle
describes cycling of elements btw land, atm, sediment and ocea
