Please enable JavaScript.
Coggle requires JavaScript to display documents.
rate of reaction - Coggle Diagram
rate of reaction
-
rate of rxn graph
gradient of curve at any time = rate of reaction at that time (rate of rxn is inversely proportional with time = shorter the time, faster the rxn)
steeper the gradient, faster the rate of rxn (rate = 1/time)
e.g. gradient is steepest at the beginning. as time progresses, gradient of the graph decreases as the no. of reactant particles per unit volume/ concentration of acid is the highest. as reactants are used up, the gradient becomes less steep and the reaction becomes slower. gradient is zero when limiting reactant is used up.
collision theory
particles must collide to react but not all collisions result in a reaction. all colliding particles need a minimum amount of energy before a reaction can occur. this energy is called Activation Energy. When Ea is achieved, collision is called an effective collision. As the frequency of collisions increases, there will be more frequent effective collisions and thus a faster rate of reaction.
activation energy (Ea): minimum energy required by the collliding particles so that a collision results in an effective collision and new substances are formed. different reactions have different Ea and reactions with low Ea happen quickly.
-
as a reaction proceeds, reactants are being used up whilst products are being formed
to measure the rate of reaction, can
1) measure the rate at which the reactants are used up or
2) rate at which products are formed
if rxn produces a gas, rate of rxn can be obtained by measuring
1) volume of gas produced at regular time intervals (e.g. 30s) or
2) decrease in mass of reactants at regular time intervals (e.g. 30s)