OXIDATION OF SUCROSE BY POTASSIUM PERMANGANATE. 225 
Calculation of velocity constants. 
For the calculation of constants as for a reaction of the 
first order the equation 
et b 
ke pela ae lo oe 
fre bs 2 x) 
was used and for constants as for a reaction of the second 
order, the equation 
ay ose (a — x) b 
~ t(a — b) = (b - x) a 
where a is the initial concentration of sucrose, b the 
initial concentration of potassium permanganate and x 
the amount of potassium permanganate decomposed in the 
time t minutes. Concentrations are expressed throughout 
in terms of normality; and the values of x are given by 
(1 — Mo ) 4 
(nx — Np) 
where 1 is the number of ccs. of permanganate solution 
required to neutralise the excess of ferrous ammonium 
sulphate, after running in 5 ccs of the reaction mixture 
and bis as above; x is thus obtained by determination 
of the permanganate. The sucrose was not determined 
at all stages but for the calculation of the second order 
constants, the assumption was made that this reaction takes 
place between one molecule of sucrose and one molecule of 
potassium permanganate. 
a 
The order of the reaction. 
As already stated the reaction does not proceed at a 
constant rate, so that the determination of the order of the 
reaction could not be very satisfactorily calculated from 
the results of experiments made with solutions containing 
only those substances necessary for the reaction. It was 
subsequently found, as will be shown in a later paragraph, 
that the addition of a suitable amount of manganese 
sulphate to the reaction mixture causes the reaction to 
proceed at a muchmore uniform rate. This substance was 
therefore employed in the following experiments and the 
results indicate that the reaction involved is of the second 
order. 
O—July 1, 1914. 
