CHEM UNIT 3

enthalpy

energy cant be created or destroyed

in chemical bonds

endothermic

building bonds taking in energy +h

exothermic

breaking bonds releasing energy -h

kinetic

moving electrons

vibration of atoms

movement in molecules

physical

ima being worked on]

particles remain unchanged

changes of state 10 0-2

chemical

overcoming structure and binds in molecules

new substances w new bonds

10 2-4

nucleaer

overcoming forced between p and n

new atoms

10 10-12

heat capacity

amount of heat absorbed or released in change of water

calorimetry

mesures heat transfer of a system

physical - solid

chemical- aq solutions

hess law

enthalpy changes in one equation can sill be the same if that equation has multiple step

what is rate law

how fast a reaction happens based on concentrations

collison theory

right amount of energy and right orientation

activation complex

time between when reactants turn into products half broken and half formed bonds r

eaction intermediate

compounds that are used up right away

catalyst

compounds that are made uo then regenerate

RDS

slowest step in a reaction mechcanism

rae concentration

increase in conecnetration

more particles

more collisions

more effective collisons

faster rate

surface area

increase in surface area

more effective collisions

faster rate

temperature

more heat

faster

more collisoons

higher rate

maxwelll Boltzmann

statistical distribution of energy and # of molecules

area under curve is # of molecules

molecules with energy ≥ activation energy can react, so increasing temperature or lowering Ea increases the reaction rate.

natur elf chemical reactant

change geometry of the element causing a faster rate

change ea lower threshold of ea so more particles can collide effectively causes a faster rate

catalyst

speed yp reaction without being vonsumed

lower activation energy

more molecules can reach threshold

more collisions so faster rate

collision theory

collisions must have enough energy to break and make bonds

you need the right orientation for the actual making and breaking to happen

how to increase effective collisions

increase the number of atoms that collide

provides more energy

activation energy

amount of energy needed for an effective collision to occur

certain bonds require more or less energy to break apart

activation complex

maximum potential energy is formed here

basically right before reactants turn into products so half of the bonds are broke while the other half of them are built