Factors Affecting Reaction Ratesmrlittles.weebly.com/uploads/1/0/4/3/10438176/factors... · 2018....
Transcript of Factors Affecting Reaction Ratesmrlittles.weebly.com/uploads/1/0/4/3/10438176/factors... · 2018....
Factors Affecting ReactionRates
FACTORS AFFECTINGREACTION RATE
There are five factors affecting rate:
P Chemical nature of reactants
P Concentration of reactants
P Temperature
P Presence of a catalyst
P Surface area
Chemical Nature of Reactants
P simple atoms/ions reactmuch faster than morecomplex ones
P due to the number of bondsthat need to be broken andreformed Potassium
metal
Calcium metal
Video
Concentration
P if the initialconcentration ofreactants in areaction isincreased, generallythe rate of reactionincreases
P this is due to thenumber ofatoms/moleculesthat are available toreact
Temperature
P as the temperature of a systemincreases, the rate of reactionincreases
P this is due to an increase inkinetic energy within theatoms/molecules, which allowsthem to move faster/farther,making the contact with theother atoms/molecules that isnecessary for the reaction toproceed
P general rule of thumb is: a 10E Cincrease in temperature resultsin a double or triple rate ofreaction (at SATP)
Presence of a Catalyst
P catalyst - is a substance thatalters the rate of a chemicalreaction without itself beingpermanently changed.
P most catalysts have beendiscovered by trial and error
P examples include catalyticconverters in car engines;chlorophyll is the catalystduring photosynthesis;enzymes in biologicalprocesses
Surface Area
P as the surface area of thereactants are increased, therate of reaction increases
P during a heterogeneousreaction, the reaction occurswhere the two phasesactually come into contactwith each other.
P therefore, when more surfacearea of one of the reactants isexposed and comes intocontact with the otherreactant, the rate of thereaction will increase
Homework:
Read pages 367 -370
Complete # 3 - 6 (Practice) pg. 371
# 1 (Section Questions) pg. 371