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#### Nitin_Naudiyal

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##### Chemical Kinetics - First Order Reaction
« on: December 04, 2012, 08:01:08 PM »

For the Decomposition of Ethylene Oxide into CH4 and CO, the variation of total pressure P of the reaction Mixture with time is given below:

t/s    P/mm
0       120
300    127.2
600    134
900    140.3

Show that the reaction is First order?

Here, Let Pi = Initial Pressure of ethylene oxide and PA = Partial Pressure of ethylene Oxide at time t.
If x = decrease in pressure in ethylene oxide all at time t then PA = Pi - x

My question is -
If the pressure of ethylene oxide decreases by x at time t, then pressure of CH4 and CO will increase by x each, or by x/2 each?
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#### curiouscat

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##### Re: Chemical Kinetics - First Order Reaction
« Reply #1 on: December 04, 2012, 08:17:14 PM »

Write the balanced eq. first.
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#### Nitin_Naudiyal

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##### Re: Chemical Kinetics - First Order Reaction
« Reply #2 on: December 04, 2012, 09:25:16 PM »

Write the balanced eq. first.

C2H4O(g) :rarrow:CH4(g) + CO(g)
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#### curiouscat

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##### Re: Chemical Kinetics - First Order Reaction
« Reply #3 on: December 04, 2012, 09:58:02 PM »

Show your attempt. What eq. do you know.
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#### Nitin_Naudiyal

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##### Re: Chemical Kinetics - First Order Reaction
« Reply #4 on: December 04, 2012, 10:30:41 PM »

Show your attempt. What eq. do you know.

Here, Let Pi = Initial Pressure of ethylene oxide and PA = Partial Pressure of ethylene Oxide at time t.
If x = decrease in pressure in ethylene oxide all at time t then PA = Pi - x

Then, P = PA + x + x = Pi - x + x + x = Pi + x
Hence,x = P - Pi

Thus, PA = Pi - x = Pi - P + Pi  = 2Pi - P

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#### curiouscat

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##### Re: Chemical Kinetics - First Order Reaction
« Reply #5 on: December 04, 2012, 10:46:09 PM »

The answer I get is "will increase by x each"
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