equilibrium 1 Flashcards
(13 cards)
how does dynamic equilibrium occur overall
ONLY APPLIES TO REVERSIBLE REACTIONS
- at start, high conc of reactants so fast rate in forward direction
- as product conc increases, rate of reverse reaction increases
- rate of forward and reverse become the same, conc of R+P remain constant (but not necessarily the same as each other)
what does Le Chatelier’s Principle state
a system (the chemicals) will counteract any change imposed upon it
how does change in concentration effect position of equilibrium
if concentration of reactant increases, position shifts right (amount of product increases)
if concentration of product increases, position shifts left (more reactants to use up products)
how does change in temperature affect position of equilibrium
increase in temp shifts position in ENDOTHERMIC direction (backwards reaction), decrease yield
how does change in pressure affect position of equilibrium
ONLY SUBSTANCES IN GAS STATE
increase n pressure shifts position to side with fewer gas moles
affect of catalyst on position of equilibrium
does not change position as increases rate of forward and reverse reactions equally - lower activation energy
homogeneous system
reactants and products are in same phase
heterogeneous system
reactants and/or products are in different phases
reaction quotient Q
mathematical relationship between concentration of reactants and products
when can Q be calculated and what is expression
any point during reaction, same expression as Kc
when can Kc be calculated
only at equilibrium (equilibrium constant)
Kc expression
products in [] to power of molar ratio divided by reactants in [] to power of molar ratio
how to calculate value for Kc
ICE table, work out equilibrium concentration with C=m/v (dm3), put into Kc expression
