For a first order reaction, the initial reactant concentration, [A]o, is 0.76 M. After 17.7 s, the concentration is 0.65 M. What is [A] after 67 s? Hint given in feedback Answer: X Do the problem in 2 steps. First find k and then the new concentration. For the reaction A B + C when [A] is plotted versus the time in minutes a straight line is obtained whose slope is -0.025 M/min. What is the concentration of A (in M) after 25.00 min if [A] = 0.80 M? Answer: x Act Go 1