GENERAL CHEMISTRY
EXPERIMENT-3
CHEMICAL KINETICS
PREPARED BY BURAK COBAN
PURPOSE:
In this experiment we will study the rate of decomposition of hydrogen peroxide to form oxygen according to the net equation:
2H2O2 (aq) 2H2O(l) + O2
by measuring the rate at which oxygen evolved, we will investigate how the rate changes with varying initial concentrations of hydrogen peroxide and iodide catalyst. After we will study the affect of changing its concentration the rate oxygen evolution. At the end of experiment we will summarize our results by attempting to write a rate law for the reaction, showing the defences on the concentrations of H2O2 and I.
THEORY:
Chemical reactions can be fast (think of any explosion ) or slow . It is very important to understand what is affecting the rate of the reaction and what is the mechanism of the reaction with such knowledge, we can often control a reaction to proceed at just the speed we need. we can thus avoid an explosion or speed up a reaction that seems too slow.
In this chapter we start out by discussing rates of reactions and the rate law. The rate law indicates the affect that the concentration of the reactants has on the reaction rate. In general, adding more of a reactant speeds things up (rather like pushing the gas pedal to put more gas into the car engine ). But how much faster is the reaction if say the concentration of a reactant is doubled ? the rate law will help us answer such equations.
Another way to affect the rate of a reaction is to change the temperature. We refrigerate food to slow the rate of bacterial metabolism that can cause food to spoil. If we want food to cook faster, we increase the heat. We also look at why some reactions seem to need a “kick start,” although once started, they continue to react. We will examine the activation barrier to reactions and its