A student wants to determine the rate constant for the reaction between hydrogen and iodine gases, given the following experimental data:-At t=0, the initial concentration of hydrogen is 0.025 M and iodine is 0.015 M.-10 seconds later, the concentration of hydrogen is 0.018 M and iodine is 0.022 M.-The reaction is second-order with respect to hydrogen, and first-order with respect to iodine.What is the rate constant for the reaction?

Question

A student wants to determine the rate constant for the reaction between hydrogen and iodine gases, given the following experimental data:-At t=0, the initial concentration of hydrogen is 0.025 M and iodine is 0.015 M.-10 seconds later, the concentration of hydrogen is 0.018 M and iodine is 0.022 M.-The reaction is second-order with respect to hydroge

Answer 1

To determine the rate constant for the reaction, we first need to write the rate law for the reaction. Since the reaction is second-order with respect to hydrogen  H2  and first-order with respect to iodine  I2 , the rate law is:rate = k[H2]^2[I2]We can use the initial and final concentrations of hydrogen and iodine to calculate the rate of the reaction. The change in concentration of hydrogen is:[H2] = 0.025 M - 0.018 M = 0.007 MThis change occurs over a time period of 10 seconds, so the average rate of the reaction is:rate = [H2] / t = 0.007 M / 10 s = 7.0 x 10^-4 M/sNow we can plug the initial concentrations of hydrogen and iodine, as well as the calculated rate, into the rate law equation to solve for the rate constant k:7.0 x 10^-4 M/s = k 0.025 M ^2 0.015 M Now, we can solve for k:k =  7.0 x 10^-4 M/s  /   0.025 M ^2 0.015 M  k  6.24 x 10^-3 M^-2s^-1So, the rate constant for the reaction is approximately 6.24 x 10^-3 M^-2s^-1.