34. Solving a chemistry problem

19. When studying the kinetics of thermal decomposition of substance A, the initial concentration of which is 100 mol / m3, the values of the reaction rate constants at different temperatures were obtained
T,K 810 830 840 850 870
k, min-1 0.003 0.0061 0.0088 0.0123 0.0242
Determine: 1) by a graphical method the value of the activation energy;
2) calculate the value of the pre-exponential factor;
3) calculate the concentration of the initial substance after 15 minutes from the start of the reaction proceeding at a temperature of 840 K.