Rates of reaction and energy changes Flashcards
three ways that rates of reactions can be measured
a. if a reaction produces a gas( volume of gas is measured)
b. measuring decrease in mass of a reactant
c. if reaction produces precipitate(gets solid)
what is the collision theory
It states that the rate of a chemical reaction is proportional to the number of collisions between reactant molecules.
the more often reactant molecules collide, the more they react with another and the faster the reaction rate.
For collison to be succesful what must happen
a. particles must collide with one another
b. particles must have proper orientation
c. there must be sufficent energy(activation energy)
the rates of chemical reaction are affect by 4 whats
a. temparature.
b. catlyst
c. size of particles
d. concentration
explain how increase in temparature affects rates of reaction
a. Energy of particles will increase
b. number of particles with energy will increase
c. number of collisions per unit time increases
d. number of successful collisions per unit time increases.
explain how the increase in concentration affects the rates of reaction.
a. number of particles per unit volume increases
b. number of collisions per unit time increases
c. number of successful collision per unit time increase.
explain how the size of particles affects the rates of reactions
smaller particles have great surface area and bigger particles have small surface area. so the smaller particles with great surface are will have an increase collision per unity time which means increase in rates of reaction
explain how catalyst affect the rates of reaction.
Catalyst speeds up chemical reaction by reducing activation energy. therefore there will be more particle s with the minimum energy required to react thus speeding the reaction rate.
the energy of reaction
the net change of chemical potential energy of the sytsem
when bonds are broken energy
is taken in which is endothermic
when bonds are formed energy
is released exothemic
endothermic absorbs heat
thus decreasing the temprature of reaction mixutere
exothermic releases heat
thus increasing temprature of the reaction mixture.
