Task: Question Answering
Input (English): Question: In the kinetic methods of analysis: 
 Options:  <1> Slow reactions can be used. <2> It is necessary that the reaction be completed in order to obtain the data of the equilibrium concentrations. <3> Low concentrations of a catalyst can be determined as long as the speed of the reaction does not depend on the concentration thereof. <4> It is not necessary to rigorously control the experimental conditions. <5> Mixtures of analytes can be determined as long as they all react with the same reagent at the same reaction rate.
Output (English): 1