Water and Seawater Water Molecules and their Characteristics

Water and Seawater Water Molecules and their Characteristics

Atomic Structure • The chemical properties of water are essential for sustaining all life forms. – Composing 65% of humans and 95% of plants – Huma BLOOD is 83% water • An atom are the basic building blocks of all matter

Atomic Structure • Atoms are composed of protons, neutron, and electron – Same amount of proton and neutron – To balanced the charge also same amount of electrons • The number of protons is what makes each element different from one another – The number of electrons can change making the atom have a charge ions • Oxygen- 8 protons, 8 neutrons, 8 electrons • Hydrogen- 1 proton, 1 neutron, 1 electron

Atomic Structure • Molecule is a group of two or more atoms held together by mutually shared electrons • Water Molecule H 2 O- one oxygen atom covalently bonded to two hydrogen atoms at an angle of 104. 5 degrees

Intermolecular Forces • The oxygen and hydrogen are covalently binds to each other this is a strong bonds form due to sharing of electrons • The Bent geometry gives a negative charge to the oxygen side and a positive charge to the hydrogen side of the molecule • Water is a polar molecule – Has a partial positive and a partial negative side – The oxygen is partial negative – The hydrogen is partial positive

Hydrogen Bond • Attraction between positive and negative ends of water molecules to each other or other ions • Oxygen, forms a weak H bond • The hydrogen bond is much weaker than a covalent bond • Less energy is needed to be broken

Properties of Water Due to H Bonds • Cohesion- water molecules stick to one another, causes it to bead up on waxed surfaces • Surface Tension- Water’s surface has a thin “skin”. It’s a result from the formation of hydrogen bonds between the outermost layer of water

Properties of Water Due to H Bonds • Adhesion- water clings to surfaces, will climb up the sides of a glass test tube • Capillary Action- very thin tubes will allow water to climb up tube, Plants use capillary action to raise water to tops of trees

Properties of Water Due to H Bonds • Universal Solvent- Water is able to dissolve nearly everything, given time it can dissolve more substances in greater quantity than any known substance – Water sticks to other polar molecules, Na. Cl + sodium sticks to - oxygen and –chloride sticks to + hydrogen

Thermal Properties of Water • Water exists as a solid, Liquid and a gas at earths temperatures • Has the capacity to store and release great amounts of heat because the H bonds must be broken – These bonds are broken by either adding heat (ice water) or removing heat (water ice) • Heat is measured in calories(heat required to raise 1 gram of water 1 degree centigrade)

Thermal Properties of Water • In solid state water has a rigid structure – Bonds are constantly being broken, vibrating, by molecule remains in relative fixed position • In liquid state water has a flexible structure – Bonds are being formed and broken at a much faster rate than in solid state, molecules still interact but have more room to flow by each other • In gas state water molecules no longer interact with each other except during collision

Water Freezing and Boiling Points •

Water’s Heat Capacity •

Water’s Latent Heats • Latent heat is the amount of “hidden” heat water has stores, which is related to water's unusually high heat capacity • As water evaporates from your skin, it cools your body by absorbing heat (this is why sweating cools your body) • If you have ever been burned by water vapor, this steam released an enormous amount of latent heat when it condenses to a liquid

Thermal Properties of Water • Latent Heat of melting- to go from solid to liquid just enough H bonds are broken to allow water molecules to slide past one another. (80 calories) • Latent heat of Vaporization- to go from liquid to gas all H bonds must be broken to allow water molecules to move freely, (540 calories) water molecules vaporize into air at 1000 mph • Latent heat of Evaporation- conversion of liquid to gas below the boiling point. – To evaporate from the ocean surface at less than 100 degrees C water molecules take heat energy away from surrounding water. Molecules left behind have less heat which explains the cooling effect of evaporation ( requires 585 calories to evaporate, more H bonds must be overcome)

Thermal Properties of Water • Latent heat of Condensation Cooled water vapor turns to liquid and releases heat to the environment – releases heat back into air, cooks food as a steamer and releases enough energy to power thunderstorms and Hurricanes. • Latent Heat of Freezing Heat released when water freezes – is identical to that of melting( 80 calories)

Calories = heat being applied

Global Thermostatic Effects • The Sun radiates energy to earth where some is stored in the oceans • Evaporation removes this heat energy and carries it high into Atmosphere • Cooler upper atmosphere causes condensation into clouds and precipitation • This cycle of evaporation and condensation carries huge amounts of heat energy from lower warm latitudes to Higher colder latitudes • The heat exchange is efficient • The thermal properties of water prevent wide variations in Earths temperature, moderating Earths climate, makes life possible on Earth.

Water Density •

Seawater Salinity • Enough salt is dissolved in the ocean to cover the entire earth in 500 feet of salt • Seawater also contains chlorine, sodium, sulfur, magnesium, calcium, and potassium and 80 other chemical elements

Seawater Salinity • Salinity of the ocean is 3. 5%, usually expressed as parts per thousand (ppt) 35 ppt, or 35 grams of salt to every 1000 grams of water • Salinity variations in open ocean 33 to 38 ppt, the Baltic sea averages 10 ppt

Seawater Salinity • Brackish water- where fresh water rivers and rain mix with salt water – Lowers salinity • Hypersaline- high evaporation rates and limit open-ocean circulation – Red Sea averages 42 ppt , areas with high evaporation rates like inland Lakes, Great Salt Lake Utah 280 ppt, Dead Sea 330 ppt

Seawater Salinity • Seasonal Variations in salinity • Miami Beach – 34. 8 ppt in October to 36. 4 ppt in May and June – May – June high evaporation rate • Columbia River Oregon – 0. 3 ppt in April to 2. 6 ppt in May – Low from vast fresh water input from Columbia River • Tap water salinity below 0. 8 ppt • Processes that Effect Salinity include Precipitation, river runoff, melting and freezing sea ice, Icebergs, evaporation

Seawater Salinity • Decreasing salinity – adding fresh water to ocean – River Runoff, melting icebergs, melting sea ice – Precipitation • Increasing salinity – removing water from ocean – Sea ice formation – Evaporation

Hydrologic Cycle • Recycle water among the ocean, atmosphere and continents – Process that effects seawater salinity • • • Ocean 97. 2% Glaciers, Ice Caps 2. 15% Ground Water, Soil moister 0. 62% Rivers and Lakes 0. 02% Water Vapor in Atmosphere 0. 001%

At the surface the salinity differs a lot but not in the deep. Why is that?

High salinity (orange and red areas) occur in areas of low latitude Low salinity (blue and purple areas) occur in areas of high latitudes

Seawater Density • Halocline- rapid changes in salinity between 300 and 1000 meters, Higher salinity means higher Density • https: //youtu. be/Q 60 Xf. Lc. Smd. Y

Seawater Density • Thermocline – rapid changes in temp between 300 and 100 meters, warm surface water with layer of cold Denser water underneath – Abrupt change in density with depth

Seawater Density • Pycnocline- Layer of rapidly changing density due to Halo and Thermo, acts as a strong barrier to mixing surface and deep water – Abrupt change of temperature with depth https: //youtu. be/Txdi. U 3 LJl. Z 8

Seawater Density • The factors that affect seawater density occur at the surface of the ocean, salinity and temperature changes, the surface density can vary but the deep ocean changes very little • Water is not compressible so deep ocean pressures have little effect on the density

Carbon Dioxide CO 2 • Carbon dioxide is one of the most abundant gases dissolved in seawater • Seawater can hold almost a thousand times more CO 2 than oxygen however it is quickly used up by photosynthesis so there is usually about 60 times more CO 2 than oxygen dissolved in sea water

Acidity and Alkalinity of Seawater •

The p. H scale • p. H scale (potential of Hydrogen) measure of acidity or alkalinity of a solution • p. H measures the concentration of H+ – p. H = - log[H+ ] • p. H ranges from 0 (strong acid) to 14 (strong base)

The p. H scale • p. H value less than 7 = acid • p. H value greater than 7 = base (alkaline) • p. H 7 = neutral – Pure water same amount of H+ to OH-

p. H Scale

Acidity and Alkalinity of Seawater •

Acidity and Alkalinity of Seawater too basic drops p. H ↓ Seawater too acidic p. H rises ↓ • Carbonate Buffering System of the ocean- CO 2 combines with H 2 O to form carbonic acid (H 2 CO 3). Carbonic acid can lose an H+ to form Bicarbonate HCO 3 • The Bicarbonate can also lose its H+ to form a Carbonate ion (CO 3 -) which will combine with Ca to form Calcium Carbonate(Ca. CO 3) which is deposited on the ocean floor

Acidity and Alkalinity of Seawater • Buffering- Calcium Carbonate can come out of solution and the carbonate will pick the H back up to remove it from the water • If p. H of ocean rises (too basic) it causes H 2 CO 3 to release H and drop p. H • If p. H of ocean drops (too acidic) HCO 3 combines with H to remove it raising p. H • p. H of ocean surface averages 8. 1

Acidity and Alkalinity of Seawater • Deep-ocean water contains more carbon dioxide than surface water because deep water is cold and has the ability to dissolve more gasses • The higher pressure also helps the dissolution of gasses • When marine organisms with calcium carbonate shell die and sink to the deep ocean the neutralized acid through buffering

Acidity and Alkalinity of Seawater • The ocean appear to have removed a large amount of the atmospheric CO 2 added by fossil fuel burning during the industrial age

Acidity and Alkalinity of Seawater • The intake of so much CO 2 through time has increase the p. H of seawater. This harms animals that use calcium carbonate to make their outer shell like coral reefs and clams • https: //youtu. be/Wo-b. Ht 1 b. Osw

Vicinal Water Exotic Properties of Cell Water

Modified Water • Water molecules within a cell that are touching a cell membrane or layers close to it are modified by solvation forces • Water in a living cell has solutes like Na. Cl, potassium, magnesium, phosphate as well as fats, proteins and carbohydrates dissolved in it which change the structure of water • A cell has hundreds of surfaces, about 840 acres of cell membrane in a single cell so more than 90% of the water is Vicinal

Modified Water • Vicinal water is 3% less dense, Absorbs 25% more heat, and has greater Viscosity than nonvicinal water • The properties of water change gradually with increasing temperature, the properties of Vicinal water change Abruptly at specific temperatures 59, 86, 113, and 140 degrees F • There is an increase of 20 -30% in the ratio of potassium to Sodium at these 4 temperatures. Healthy chemical functioning of the cell depends on this ratio being maintained

Modified Water • Vicinal water change Abruptly at specific temperatures 59, 86, 113, and 140 degrees F • The mammalian body temperature of 98. 6 degrees F falls exactly in between 86 and 113, as far from the two as possible. • If 122 was the normal temp between 113 and 140 too many calories would be needed to maintain the temp • If 72 had been chosen between 56 and 89 overheating at earths average temp of would have been certain