Half life period for a reaction `A to` Products at 298 K is 3.33 hours. Calcualte the rate constant for the reaction. If the reaction is started from one mole of A, what amount of A would remain unreacted at the end of 9 hours?

Explanation

Step i. Calculation of the rate constant.
Rate constant(k)`=(0.693)/(t_(1//20))= (0.693)/(3.33 "hours")=0.2081 hr^(-1)`
Step II. Calculation of amount of A left unreacted
`k=0.2081 hr^(-1)`, a=1mol, t=9 hours.
`k=2.303/t log a/(a-x)`
`log a/(a-x) = (kxxt)/(2.303) = (0.2081 hr^(-1) xx 9hr)/(2.303) = 0.8133`
`a/(a-x) = "Antilog" 0.8133=6.506`
`(a-x) = a/6.506 = 1/(6.506)=0.1538` mol