water & carbon Flashcards
what is the orbital
location where an electron may be found a vast majority of the time
where are the electrons in the first row of the periodic table found
in a sphere in the atomic nucleus
how many orbitals do the second row of elements in the periodic table have and what are they
4 orbitals - spherical, 2py, 2px, 2pz
what happens to the orbitals when electrons are shared
they hybridize - form a tetrahedron (new shape) e.g. methane / ethane
how many degrees away from eachother are all 4 orbitals of a tetrahedron (bond angle of tetrahedron)
109.5
Bond angle of water
104.5 degrees - two lone pairs of electrons in oxygen push away from eachother, opening the angle
what kind of molecule is water
polar - unequal sharing of its electrons - oxygen strongly pulls all the electrons
what is gas
single molecules of water bind and are liberated from one another with additional energy
what is liquid
fragile disorganised hydrogen bond – last few trillionths of a second
what is solid
4 neighbors in 3d states – makes H-bonds more spaced out – less dense than liquid so it floats (expansion upon freezing)
6 emergent properties of water
- Cohesion, adhesion + surface tension (allows paper clips to float etc)
- Moderates temperature
- Evaporative cooling
- Expansion upon freezing
- Universal solvent for life
- Acid base chemistry
what does the water property cohesion mean
H-bonds holding water together – sticks to itself e.g. travels up trees
what does the water property adhesive mean
H-bonds holding water to polar or charged things e.g. why oils and water don’t mix – methane = non-polar
what does the water property moderates temperature mean
water absorbs heat from warmer air and releases to cooler air
High specific heat meaning
amount of heat that must be absorbed or lost to change temp by 1°c (takes lots of heat to break lots of hydrogen bonds) - basis for the metric system
calorie meaning
amount of energy for 1 gram of water to be raised by 1°c
what does the water property evaporative cooling mean
transfer from liquid -> gas to cool the system
High heat of vaporization meaning
amount of heat required for 1g of a substance to be raised by 1°c
what does the water property Universal solvent for life mean
water forms hydration shells around other polar or charged molecules e.g. the H+ in water will attract the Cl- in salt, O- will attract the Na+
what’s hydrophilic
polar or charged things – affinity for water (watery)
what’s hydrophobic
nonpolar or noncharged – no affinity to water (oily) - PHOBIA OF WATER
what is pH
number of H+ ions in a solution
what does it mean when Proton number is higher in a solution
acidic (things that put protons into solution)
what does it mean when Proton number is lower in a solution
bases
what rarely happens when H2O + H2O
= H3O + OH
(hydronium + hydroxide)
what mostly happens when H3O + OH
= H2O + H2O
hydronium symbol
H3O (+)
hydroxide symbol
OH (-)
what happens when H3O x OH
10 (-14)
- pH follows after the number of hydronium e.g.
10(-7) x 10(-7) = pH 7
10(-11) x 10(-3) = pH 11
how does carbon enter the biosphere
as CO2
what is carbon unique in its ability to do
to form large diverse molecules – perfect sharer for building things (creates backbones)
- Forms bands with HNOPS to make a variety of molecules
important thing to remember about carbon
PERFECT SHARER
what’s the study of carbon called
organic chemistry
what shape is Carbon linked by double bond (C = C)
trigonal planer e.g. ethene (ethylene)
trigonal planer bond angles
120 degrees
Things that can be added to hydrocarbon backbone
OH hydroxyl
C=O carbonyl
COOH carboxyl
NH2 amino
PO4 phosphate
S-H sulfhydryl
CH3 methyl
what properties emerge by adding hydroxyl group to hydrocarbon backbone
gives polar characteristic due to oxygen – WATER SOLUBLE
what properties emerge by adding carbonyl group to hydrocarbon backbone
gives polar characteristic due to oxygen – WATER SOLUBLE
what properties emerge by adding carboxyl group to hydrocarbon backbone
gives an acidic characteristic - donates H+
what properties emerge by adding amino group to hydrocarbon backbone
gives basic characteristic – can take on a proton
what properties emerge by adding Phosphate group to hydrocarbon backbone
- gives extra acidic characteristic by donating H+
- increased polarity
what properties emerge by adding sulfhydryl group to hydrocarbon backbone
- makes disulfides
- moderates polarity - no oxygen
what properties emerge by adding methyl group to hydrocarbon backbone
- nonpolar - no oxygen - hydrophobic
