Studied by 33 people
Energy
the capacity to do work
Work
is movement against force (w= fxd)
Heat
is energy that flows from a hotter to colder object
motion at the molecular level
heat
Temperature
determines that direction of heat flow and is a measure of the average speed of that motion
activation energy
the energy that is needed to start a reaction
isomer
each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties
First law of Thermodynamics
the energy of the universe is instant, or, energy can neither be created nor destroyed; but it can be converted from one form to another
Potential energy
is energy due to position or composition
kinetic energy
energy due to movement
Second Law of thermodynamics
the entropy (chaos) of the universe is increasing
Per capita
accounting for an individual or each person
Countries ranked by co2 emissions
china
US
India
Russian Federation
Japan
Germany
Bond energy
the amount of energy that must be absorbed to break a chemical bond
Bond formation
release of energy via exothermic reaction
Bond breaking
energy is absorbed by bonds via endothermic reaction
Exothermic reactions
energy is released during the course of a chemical reaction
Properties of an exothermic reaction
Heat/energy is released
net energy change is negative
reactants have more potential energy than products
Endothermic reactions
energy is absorbed during the course of a chemical reaction
Properties of an endothermic reaction
heat/ energy is absorbed
net energy change is positive
products have more potential energy than reactants
Uncatalyzed reaction
requires a higher activation energy
catalyzed reaction
requires lower activation energy
Chemical equation for the combustion of hydrocarbons
Hydrocarbon + O2 = CO2 = H2O
EX: CH4 + 2O2 = CO2 +2H2O + energy
Trigonal Planar
120
Linear
180
Bent
104.5
Trigonal pyramidal
107
Tetrahedral
109.5
the largest percentage of energy from the sun comes to the earth is this form
Infrared radiation
Greenhouse gases
gases capable of absorbing and emitting IR radiation thereby warming the atmosphere
Example of Greenhouse gases
water vapor
methane
carbon dioxide
nitrous oxide
ozone
chlorofluorocarbons
Greenhouse effect
Atmospheric gases trap and return a major portion of this heat radiating from the earth through this natural and necessary process. Without this process the Earth would freeze over and be uninhabitable. As the number of atmospheric GHGs increases this process is accelerated causing the Earth's surface temperatures to rise.
Anthropogenic Greenhouse Gases
man made activities that rely on processes that put more carbon atoms into the atmosphere rather than those that remove them; ex: cutting down rainforests, combustion
Classification of Greenhouse Gasses
3 or more atoms
the molecular geometry
ability to bend and stretch with exposure to the infrared radiation ( without breaking apart )
Ionic compound
metal bonded with nonmetal
Polyatomic ions
two or more atoms covalently bonded together that have an overall positive or negative charge
Dynamic system
natural additional and removal mechanisms
What process adds carbon to the atmosphere?
Respiration
What process removes carbon from the atmosphere?
photosynthesis
Isotopes
atoms of the same element that have the same number of protons but differ in number of neutrons, therefore they have different atomic masses
Average atomic mass
(mass of isotope)(decimal of %) + (mass of isotope)(decimal of %) = Avg. atomic mass
answer should be very similar to atomic weight
Avg. Atomic mass example
Cl35 and Cl37
(35)(.7587) + (37) (.242) = 35.51
