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The chemistry of sea water - Coggle Diagram
The chemistry of sea water
Introduction
water is unique and valuable resource, we take very much for granted, water sustains life on Earth no water= no life
Resource = limited
Interesting facts about water:
-Human body=65% water
-human blood made up of 83% water
-plants=95%water
-jelly fish=99% water
Waters life-sustaining properties all thanks to its chemistry
-Arrangement of atoms in water not linear but bent
-bonding between the molecules= hydrogen bonding
-Water found naturally in all three states (solid, liquid, gas )
-freezing point=0 degrees C
-relatively high boiling point= 100 degrees C
-universal solvent
-as waters temp decreases its density increases to a maximum density at 4 degrees C then it decreases
-ice floats on water, thus preventing ocean basins from freezing from bottom up.
-high latent heat of melting and vaporisation
-relatively high heat capacity
Heat capacity enables ocean to have a moderating influence on weather t the coast.
Basic marine science chemistry
Matter =any substance that has mass and takes up volume or space, all matter made up of atoms. Atom smallest unit of ordinary matter and gives the element its distinct properties. Every solid liquid and gas is made up of atoms.
Atoms comprise of a center nucleus containing protons and neutrons and electrons that orbit nucleus. Protons= positive, neutrons=no charge, electrons= negative
Molecule made up of 2 or more atoms held together by chemical bonds.
An element is a atom with specific and unique number of protons.
Ion is a atoms or molecule with either a positive or negative electrical charge, either having too few electrons= positively charged (Cation) or too many electrons= negatively charged (Anion)
.
Chemical compound= chemical substance made up of many of the same molecules, molecules made up of more than one element.
A mixture= combination of two or more elements that have retained their identity
Chemical bonding in water
Water molecule consists of 3 atoms 1 oxygen and 2 hydrogen positioned on either side of oxygen atom, chemical bond holding these three atoms together, bonding consists of electrons being shared between oxygen and each hydrogen atom
Unique shape
H-O-H unit not linear, the way oxygen and hydrogen atoms share their electrons cause water molecule to have an angular/ bent shape (Mickey Mouse) with 105 degree angle between hydrogens
Polar molecules
On average electrons in water molecule spend more time closer to oxygen nucleus than the hydrogen nucleus= result of geometry of water molecule, hydrogen having higher electronegativity difference in relation to oxygen atom.
Oxygen= slightly negative Hydrogen= slightly positive.
Molecule therefore has positive and negative end= polar
Oxygen end attracts positive hydrogen= hydrogen bonding
Covalent bonding
Chemical bonding formed between more than one element where there is a sharing of electrons
Chemical bond between hydrogens and oxygen in water= covalent bond
Hydrogen bonding
Water polar molecule experiences hydrogen bonding because of bent shape of molecule as a whole, as result partially positive charged side and partially negative charged
side
Characteristics of hydrogen bonding
Molecules with non polar covalent bonds have no hydrogen bonds, hydrogen bonds considered weak bonds more easily broken than covalent bonds, hydrogen bonds involved in mechanism of enzyme catalysis.
Property of water droplets to hold on to each other= Cohesion.
Another property= surface tension
