At `518^(@)C` the rate of decomposition of a sample of gaseous acetaldehyde initially at a pressure of 363 Torr, was `1.00 Torr s^(–1)` when `5%` had reacted and `0.5 Torr s^(–1)` when 33% had reacted. The order of the reaction is

Options

A. 2
B. 3
C. 1
D. 0

Answer

A

Explanation

`CH_(3)CHO to CH_(4)+CO`
Generally `r prop (a-x)` m
`r_(1)=1 "torr" s^(-1)`, when 5% reacted
`r_(2)=0.5 "torr "s^(-1)`, when 33 % reacted
`(a - x_(1)) = 0.95`(unreacted)
`(a - x_(2)) = 0.67`(unreacted)
`(r_(1))/(r_(2))=[((a-x_(1)))/((a-x_(2)))]^(m)`, `(1)/(0.5)=((0.95)/(0.67))^(m)`
`2=(1.41)^(m) implies 2= (sqrt2)^(m)`
`implies m = 2`