Reaction Rates and Equilibrium Flashcards
what is the formula for rate
change in concentration/ time (seconds)
what conditions makes a collision effective?
1) particles collide with the correct orientation
2) particles have sufficient energy to overcome activation energy
how can you determine rate of reaction??
1) measure the decrease in concentration of a reactant
2) measure the increase in concentration of a product
how can you determine rate of reaction of a gas?
1) measure decrease in mass of reactants
2) monitor volume of gas at regular time intervals
what is a catalyst?
a substance that increases rate of reaction by providing alternate pathway with lower activation energy without being used up
what is a catalyst?
a substance that increases rate of reaction by providing alternate pathway with lower activation energy without being used up
what is a homogenous catalyst
a catalyst that has the same physical state as the reactants.
how does a homogenous catalyst work?
catalyst reacts with reactants to form an intermediate which then breaks down to give the product and regenerate the catalyst
what are 2 examples of homogenous catalust
1) making esters with sulfuric acid as a catalyst
ethanoic acid and ethanol react to form the ester ( CH3COOC2H5) and h20
2) ozone depletion with chlorine radicals as catalyst
2o3 + chlorine radical —– 3o2
what are 2 examples of homogenous catalust
1) making esters with sulfuric acid as a catalyst
ethanoic acid and ethanol react to form the ester ( CH3COOC2H5) and h20
2) ozone depletion with chlorine radicals as catalyst
2o3 + chlorine radical —– 3o2
what is a heterogenous catalyst
A heterogenous catalyst has a different physical state than its reactants
how does a heterogenous catalyst work
reactant molecules are weakly adsorbed onto to surface of catalyst where reaction takes place and the product leaves the catalyst by desorption
what is autocatalysis
when the product of a reaction acts as a catalyst then speeds up the reaction as more is formed
what does le chateliers principle say
when a system in equilibrium is affected by an external , the system adjusts to the change to minimise affect of the change.
what does an increase in temperature shift equilibrium to?
increase in temperature shifts equilibrium to the endothermic side
what does a decrease in temperature shift equilibrium to?
decrease in temperature shift equilibrium to the exothermic side
how does an increase in pressure affect equilibrium position?
an increase in pressure shifts equilibrium to the side with fewer moles
what is the formula for equilibrium constant?
[A]a [B]b
what does a Kc value of 1 show?
indicates an equilibrium position halfway between reactants and products
what does a Kc value of more than one show?
indicates equilibrium position is towards products
what does a Kc value of less than one show?
indicates equilibrium position is towards reactants
what colour is chlorine water
colourless
what colour is bromine water
orange
what colour is iodine water
brown
what does chlorine water form when added to KCL
colourless, no reaction
what colour does chlorine water form when added to KBr
orange as bromine is displaced by chlorine and bromine is orange
what colour does chlorine water form when added to KI
brown as iodine is displaced by chlorine and iodine is brown
what colour does chlorine water form when added to KI
brown as iodine is displaced by chlorine and iodine is brown
what colour does bromine water form when added to KCL
no change in colour so remains orange as bromine is less reactive
what colour does bromine water form when added to KBr
colour remains orange as there is no reaction
what colour does bromine water form when added to KI
colour turns brown as iodine is displaced by bromine and iodine is brown
what colour does iodine water from when added to KCL and KBr and KI
colour remains brown as doesnt displace any of the halogens
what is the order of reactivity of chlorine, bromine and iodine
chlorine> bromine>iodine
