chem12 unit1 kinetics

factors that change rxn rate + why

concentration, pressure, temperature, catalyst/inhibitor, surface area, nature of reactants

monitoring rxn by measuring change in

mass, colour, pressure, temp, pH

rate of rxn

spped at which a reaction occurs

the rate at a particular time is found by

using the slope of the tangent line on concentration-time curve

characteristics of fastest reactants in order

1 oppisitely charged aq ions

2 few or weak bonds

3 homogenous

4 2 particle collision

collision effectiveness 2 factors:

shape/orientation and activation energy

activation energy

mininum amount of engery need for reaction to occur (form activated complex)

increasing temperature and concentration increases..

collision frequency, therefore speed up rxns (same %success)

triangle H

is enthalpy= H(p) -H®

potential inc when and dec when

inc: bonds break dec: bonds form

when reactant molecules approach, they

slow down aka gain potential energy

activated complex

high energy (unstable/temporary) arrangements of atoms which occurs when reactants are in the process of rearranging to form products

high Ea means faster or slower rate?

slower

elementary process

individual steps on a reaction mechanism

reaction mechanism

sequence of steps which make up an overall reaction

each step has its own..

peak

rate determining step

slowest step in a mechanism

how does catalyst affect activation energy

provides an alternative mecahnism, lower Ea

common catalysts

platinum, catalytic converter, H+ (aq) found in acids