The decomposition of hydrogen peroxide in an aqueous solution is a reaction of first order. It can be followed by titrating 10 mL portions of reaction mixture at various times from the beginning of reaction against a standard solution of KMnO4. Volume of KMnO4 solution used in each case is proportional to the remaining concentration of H2O2. From the following data, calculate the rate constant of the reaction.
Time (in seconds)06001200KMnO4 sol. used (in mL)22.813.88.20