Participation Points Question At 25C, hydrogen iodide (HI) breaks down very slowly to hydrogen (H2) and iodine (I2). If 0.0100 moles of HI is placed in a 1.0L container, how long will it take for the concentration of HI to reach 0.00900M(10% reacted)? Rate =k[HI]2k=2.41021M1s1 Is this reaction 1st or 2nd order? 4.61021s 3. 2.41021s So we use the 2nd order integrated rate law 2.5103s [A]t1[A]01=kt Participation Points Question At 25C, hydrogen iodide (HI) breaks down very slowly to hydrogen (H2) and iodine (I2). If 0.0100 moles of HI is placed in a 1.0L container, how long will it take for the concentration of HI to reach 0.00900M(10% reacted)? Rate =k[HI]2k=2.41021M1s1 Is this reaction 1st or 2nd order? 4.61021s 3. 2.41021s So we use the 2nd order integrated rate law 2.5103s [A]t1[A]01=kt