rate, equilibrium and yield Flashcards
collision theory
particles must collide with correct orientation and sufficient energy in order to disrupt bonds in the molecule –> form a successful collision
maxwell boltzmann distribution
- demonstrates a range of energies of particles (kinetic)
-area under the curve is equal to the total number of particles in the sample - for reaction the particles must have enoigh energy to overcome activation energy.
activation energy
- Ea is minimum amount of energy required to generate a reaction
rate of reaction
- the speed at which a reaction occurs
- ror is measured by change in concentration of a reactant or product per unit time
factors affecting ROR
- SA, temp, concentration, pressure of gases, catalyst
how does SA influence ROR
- increasing the SA, increase frequency of fruitful / successful collisions bw particles will increase ROR
how does conc. influence ROR?
increasing concentration, increase successful collisions will increase ROR
how does pressure affect ROR?
increase frequency of successful collisions per unit time - done by decreasing the volumw of a container/vessel b/c decrease space for particles to collide
catalysts influencing ROR
-provides an alternate pathway by lowering activation energy for a particular reaction
- particles on the surface distort and disrupt the bonds w/in molecules hence lowers Ea required for reaction-> greater proportion of particles w energy greater than Ea and successful collisions - increase ROR
effect of temp on ROR
-increase proportion of particles with sufficient energy for a reaction - increase proportion of successful collisions
ways to measure ROR
to determine how fast a reaction occurs:
- measure rate of gas production
- measure change in mass
- for reaction w acids and bases - measure change in pH over time
- if produces a precipitate then measure time it takes for solution to become cloudy
extent of reaction
how far a chemical reaction proceeds
type of catalysts
- homogenous - same state as reactant+ product
-heterogenous - different state to reactants + products
equilibria - a closed system
-when forward and back reactions OCCUR at the same rate the reaction is at equilibrium
- occur in reversible reaction
key factors of equilibrium
- amount (mol and mass) of chemical substances are constant
- conc. of chem. substances are constant
-total gas pressure is constant
-temperature is constant
equilibrium law expression
K= (C)c x (D)d
—————
(A)a x (B)b
what is K a measure of
the extent of a reaction ,not ROR
what influences equilibrium constant (K)
- changes with temp
- not depend on initial conc. of substances
equilibrium constant - extent of reaction
. bw 10^-4 and 10^4 = significant
. > 10^4 = almost complete
. <10^-4 = negligible reaction