In an investigation of the kinetics of the reaction MnO_(4)^(-)+Cr^(3+) rarr CrO_(4)^(2-)+ Mn^(4+) at 25^(@) C False and Roller measured the times required to carry the reaction to various degrees of completion, first as a function of MnO_(4)^(-) concentration and then as a function of Cr^(3+) concentration. In each case after difinite intervals of time, 25 ml aliquots of the reaction mixture were removed and added rapidly to a solution containing 60 ml of 1.2M H_(2)SO_(4) and 25 ml of 0.5 M KBr to occur the following reaction 2MnO_(4)^(-)+10Br^(-)+16H^(+) rarr 2Mn^(2+)+5Br_(2)+8H_(2)O Free bromine instantly liberated was extracted by CS_(2)The Cr_(2)O_(7)^(2-) That had been formed by the reaction 2Cr_(4)^(2-)+2H^(+) rarr Cr_(2)O_(7)^(2-)+H_(2)O Was titrated with 0.01 N FeSO_(4) in the reaction Cr_(2)O_(7)^(2-)+6Fe^(2+)+16H^(+)+2SO_(4)^(2-) rarr 2Cr^(3+)+6Fe^(3+)+2HSO_(4)^(-)+7H_(2)O The number of millilitres of 0.01 N Cr_(2)O_(7)^(2-) Present in the mixture at the indicated reaction time is given in the table In a set of three experiments the result were as follows: {:(,"Experiment No",,"I",,"II",,"III"),(,[MnO_(4)^(-)](mol//l t),,1,,2,,1),(,[Cr^(3+)](mol//l t),,1,,1,,0.5),(,Volume of Cr_(2)O_(7)^(2-)(0.01N)present(ml),,"Time taken (min)",,,,),(,,,"I",,"II",,"III"),(,0.1,,22 min,,11 min,,45 min),(,0.2,,36 min,,18 min,,72 min),(,0.4,,60 min,,30 min,,121 min),(,0.6,,80 min,,40 min,,162 min):} Overall order and type of reaction are respectively: