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In this exam question it comes to a first order reaction and its conversion and temperature
dependence. It's about the classic laboratory experiment - the decay of sucrose into glucose
and fructose ( making inverted sugar) . The reaction has a first order rate law with a
rate constant of 0.035 1/min at 25 ° C . After which reaction time 99% conversion is reached
at 25 ° C ? To solve this problem, we need the integrated rate law : [ concentration
] = [ initial concentration ] ° by e to the ( - k times t). [ Concentration ] / [ concentration
] ° we can formulate as 1% through 100 %. ( 99% conversion means 1% sucrose ) . We solve the
equation with respect to time and obtain 131.6 min reaction time. The activation energy of
the reaction is 30 kJ / mol. What is the rate constant at 60 ° C? We use Arrhenius´s equation
for the solution of this problem . We use the activation energy (in J / mol) , set T
and T´ in Kelvins , solve for k´ and obtain k '= 0.102 1/min .