For the first-order reaction below, the concentration of product b after 24.2 seconds is 0.322 m. if k-8.75 x 105 what was the initial concentration of a? a2b rate = k[a] a. 0.183 m b. 0.0341 m c. 1.34 m d. 2.68 m e. 29.3 m atm, cl2 = 2.5 x 16. for the reaction below, the partial pressures of gases at equilibrium are as follows: h2 = 7.1 x 10 "0 atm, and hci = 3.0 atm. what is the value of the equilibrium constant, k? h2(g) + cl2(g) 2hci(g) a. 1.6 ã 10-9 b. 5.9 x 10-11 c. 1,7ã 1010 d. 2.0 x 10-11 e. 5.1 ã 1510