rate of reaction Flashcards
what must happen for a chemical reaction to occur between reactants?
reacting particles must collide + particles must collide in the correct orientation + particles need to collide with a minimum amount of energy called the activation energy
what does activation energy refer to?
minimum amount of energy that reactant particles must possess in order for a chemical reaction to occur
what does the speed/rate of reaction depend on?
the frequency of effective collisions between reactant particles/no. of effective collisions per unit time
what is the relationship between the frequency of effective collisions and the speed of reaction increases?
when the frequency of effective collisions increases, the speed of reaction increases
why does the speed of reaction increase when the temperature increases?
when temperature increases, particles gain kinetic energy and move faster which allows more reactant particles will collide with energy greater than activation energy and increases the frequency of effective collisions and thus the speed of reaction increases
why does the speed of reaction increase in a solution?
at a higher concentration, there are more particles per unit volume, increasing the frequency of effective collisions and increasing the speed of reaction
how does increasing the number of moles of the reactant affect the amount of products?
increasing the concentration of a reactant could also result in the increase in the amount of products provided that the reactant is the limiting reactant
why does the speed of reaction increase when increasing he pressure of gaseous reactants?
at higher pressure, reactant particles are closer together and there are more particles per unit volume and increases the frequency of effective collision and increases the speed of reaction increases
how can you increase the pressure of a gas in a reacting vessel?
increasing the number of reacting particles in the same volume/dec reading the volume of the vessel while the number of reacting particles remain the same
why does the speed of reaction increase when the surface area increases?
the total exposed surface area in contact with reactant particles is larger and this increase in the frequency of effective collisions, increasing the speed of reaction
what does surface area refer to?
the area of contact in which collisions of reactant particles take place
how does stirring affect the speed of reaction?
it causes large solid particles to break into smaller particles, increasing the speed of reaction
what is a catalyst?
a substance that increases the speed of a chemical reaction and remains chemically unchanged at the end of the reaction
