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Question
For the first order thermal decomposition reaction, the following data were obtained:
Time / sec Totalpressure / atm
0 0.30
300 0.50
Calculate the rate constant
(Given: log 2 = 0.301, log3 = 0.4771, log 4 = 0.6021)
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Solution
Given :
Pi = 0.30 atm
Pt = 0.50 atm
C2H5Cl(g)→C2H4(g)+HCl(g)
Pi 0 0 (At t = 0 sec)
Pi-x x x (At t = 300 sec)
So,
Pi - x + x + x = Pt
0.3+x = 0.5
x = 0.2
Then, Pi - x = 0.3 - 0.2 = 0.1 atm
For first order reaction,
`k=2.303/tlog(P_i/(P_i-x))`
`=2.303/tlog(0.3/0.1)`
`=(2.303xxlog3)/300=(2.303xx0.4771)/300`
k = 0.0037 s-1
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