In: Chemistry
At 700 K acetaldehyde decomposes in the gas phase to methane and
carbon monoxide. The reaction
isCH3CHO(g)?CH4(g)+CO(g)
A sample of CH3CHO is heated to 700 K and the pressure is measured
as 0.20 atm before any reaction takes place. The kinetics of the
reaction are then followed by measurements of total pressure and
these data are obtained:
t(s) | 0 | 1000 | 3000 | 7000 |
PTotal (atm) | 0.20 | 0.22 | 0.24 | 0.28 |
Rate law --> Rate=??PCH3CHO?t=4.510?4atm?1?s?1PCH3CHO2
Find total pressure after 1.17104s
The reaction is:
CH3COH(g) ? CH4(g) + CO(g)
At t=0: 0.2 atm 0 0
A t=t: 0.2 -x x x
Ptotal= P(CH3COH) + P(CH4) +P(CO)= 0.2 - x + x + x = 0.2 + x
x = Ptotal -0.2 (atm)
At t=0 s: x = 0 atm ?P(CH3COH) = 0.2 atm
At t = 1000 s: x = 0.02 atm ?P(CH3COH) = 0.18 atm
At t = 3000 s: x = 0.04 atm ?P(CH3COH) = 0.16 atm
At t = 3000 s: x = 0.08 atm ?P(CH3COH) = 0.12 atm
The rate law of the reaction is: rate = r = -d{P(CH3COH)/dt = k