question_answer 30)

The following data were obtained during first order thermal decomposition of SO2Cl2 at a constant volume.

t (sec)	0	100
Total pressure (atm)	0.5	0.6

Calculate the rate of the reaction when the total pressure is 0.65 atm.  

Answer:

Step I. Calculation of rate constant (k) SO2Cl2(g)  SO2 (g) + Cl2 (g) At time (t) = 0           0.5 atm             0           0 At time (t) = 100s (0.5? x) atm      x atm   x atm As decomposition of SO2Cl2 is a first order reaction of gaseous nature. Rate equation is;   = 2.23 × 10?3 s?1 Step II. Calculation of reaction rate when total pressure is 0.65 atm. pi + x = 0.65 atm x = 0.65 ? pi = 0.65 ? 0.5 = 0.15 atm Pressure of SO2Cl2 at time ?t?, and        k = 2.23 x 10?3 s?1  rate = (2.23 x 10?2 S?1) x (0.35 atm) = 7.8 x 10?4 atm s?1.