##### The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume.SO2Cl2(g)→ SO2 (g) + Cl2 (g)ExperimentTime/s–1Total pressure/atm100.521000.6Calculate the rate of the reaction when total pressure is 0.65 atm

When t = 0, the total partial pressure is P0 = 0.5 atm

When time t = t, the total partial pressure is Pt = P0 + p

P0-p = Pt-2p, but by the above equation, we know p = Pt-P0

Hence, P0-p = Pt-2(Pt-P0)

Thus, P0-p = 2P0 – Pt

We know that time

Where, k- rate constant

[R]° -Initial concentration of reactant

[R]-Concentration of reactant at time ‘t’

Here concentration can be replaced by the corresponding partial pressures.

Hence, the equation becomes,

equation 1

At time t = 100 s, Pt = 0.6 atm and P0 = 0.5 atm,

Substituting in equation 1,

Thus, k = 2.231 × 10-3 s-1

The rate of reaction R = k × PS02Cl2

When total pressure Pt = 0.65 atm and P0 = 0.5 atm, then

PS02Cl2 = 2P0-Pt

Thus, substituting the values, PS02Cl2 = 2(0.5)-0.6 = 0.35 atm

R = k × PS02Cl2 = 2.231 × 10-3 s–1 × 0.35

Rate of the reaction R = 7.8 × 10-4atm s–1

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