rates and equillibrium (C8) Flashcards
how can you calculate the rate of reaction on a graph
the graph will be curved, so you need to construct a right angled traingle, where the hypotenuse only touches one part of the curve, making a tangent, now you find the gradient by doing rise over run, and finally put your answers units in accorrdingly (usually grams/second)
what are the 2 formulae for rate of reaction
mean rate of reaction = amount of reactant used / change in time
OR
mean rate of reaction = amount of product made / change in time
how does surface area affect rate of reaction
more surface area means more collisions between particles can happen, meaning a faster reaction
what is activation energy
minimum amount of energy needed to start a reaction
how do catalysts increase rate of reaction
they provide another pathway for the reaction to happen by reducing activation energy
how does temperature change the rate of reaction
more temp, more energy in the particles means they move more, increasing chances of collisions happening
how does increasing pressure and concentration change rate of reaction
both things mean particles are closer together, and more likely to collide
in reversible reactions, wich reaction is exothermic and endothermic
exothermic is forward reaction, endothermic is the reverse reaction
what is a dynamic equillibrium
when the forward and reverse reaction take place at the same rate
what is le chateliers principle
when a change in conditions is introduced into a reversible reaction, the equillibrium shifts to the according side to cancel out the change and maintain equillibrium
if there is a higher temp in a reversible reaction, what happens in the reaction to equal out the change
the equillibrium favours the reverse (endothermic) reaction, this is because more heat means more exothermic reaction is happening (to the right), so to cancel this out the equillibrium shifts left for the endothermic reaction
define pressure
the amount of particles per said amount of volume
if there is a higher pressure in a reversible reaction, what happens in the reaction to equal out the change
higher pressure means the equillibrium will favour the side with less molecules to cancel out the change, say we 4 molecules on the left and 2 molecules on the right, the equillibrium would shift right to the side with less molecules to cancel out the change
if there is a higher concentration of reactants in a reversible reaction, what happens in the reaction to equal out the change
the equillibrium shifts to the right side wich has the products, therefore the reaction produces more product to equal out the adding of concentration to the left side
