9. (5 points) An over-all reaction consists of two elementary reactions which are 2NO2(g) → NO(g) + NO(g) -> slow (the rate constant is k) NO3(g) + CO(g) → NO2(g) + CO2(g) fast Write the rate law for the over-all reaction. 10. (5 points) The rate of a chemical reaction 2A + B2C (k is the rate constant) is expressed by Rate = k [A][B]" and we want to determine the orders of the reaction m and n from the results of the following two experiments. (Exp 1) The rate is tripled when while the concentration of B is tripled while the concentration of A is fixed. (Exp 2) The rate is quadrupled when the concentration of A is doubled while the concentration of B is fixed. What are m and n? 11. (5 points) The rate law for A2 → 2A reaction is given by == Rate = -d[A2]/dt = k[A2], first order to A2. (a) Can you express the concentration c of A2 at time t as a function of k, c, and t? The concentration of A2 at t=0 is Co. (b) Suppose it takes 1 second for the concentration (mol ) of A₂ to be 25% of the initial concentration. What is the rate constant k? (Don't forget to put the unit and show your work. 4