2080 Chemistry Spring 2009
Problem Set #3 - due date: Friday February 19th at 2 pm Name:________________ Lab TA Name:__________________ Lab Day/Time:______________________ 1) A commercial process for making nitric acid starts with the platinum-catalyzed oxidation of ammonia (NH3) by oxygen, to form nitric oxide (NO). The unbalanced chemical equation for this reaction is as follows: Pt N H3(g) + O2(g) > NO(g) + H2O(g)
First balance this chemical equation, and then use the data of Table 7.2 in the Petrucci textbook to calculate the standard enthalpy change for the balanced equation.
2) Here is a set of data showing initial versus rates concentration for reactants A, B, and C, which react together to form product D by way of the equation: A + 2B + C > D Run number: [A] (M) 0.10 0.10 0.20 0.10 [B] (M) 0.20 0.40 0.10 0.20 [C] (M) 0.050 0.050 0.050 0.100 Initial Rate of consumption of [A] ____in M/sec_____ 2.6 x 10-3 5.3 x 10-3 5.2 x 10-3 2.07 x 10-2
1) 2) 3) 4)
Find the rate law for the initial rate, namely the values of the exponents a, b and c in the rate law: Rate = k[A]a x [B]b x [C]c Calculate the value of the rate constant k, and then calculate what the inital rate would be if the initial concentrations were [A] =[B] = [C] = 0.20 M