26. Solving a chemistry problem

3. The kinetics of the decomposition reaction of phenyldiazonium chloride in water at a temperature of 40 C is described by a first-order equation with a rate constant k1. How long must a solution with an initial concentration of 0.1 mol·L−1 be kept at this temperature for its concentration to decrease by 20 times? How long will it take to achieve the same concentration in the case of a solution with an initial concentration of 0.05 mol•L−1?