The evaporation of 130 nm of film of n-pentane from a singlecrystal of aluminum

Question

The evaporation of 130 nm of film of n-pentane from a singlecrystal of aluminum oxide was found to be zero-order with the rateconstant of 1.92x1013 molecules/cm2 *s at 120K. Part A. If the initial surface coverage is 8.9x1016molecules/cm2 , how long will it take for one-half ofthe film to evaporate?      t1/2 = Part B What fraction of the film will be left after 12 s? Assume thesame initial coverage as in part A.     The evaporation of 130 nm of film of n - pentane from a singlecrystal of aluminum oxide was found to be zero - order with the rateconstant of 1.92x10^13 molecules/cm^2 *s at 120K. Part A. If the initial surface coverage is 8.9x10^16molecules/cm^2 , how long will it take for one - half ofthe film to evaporate? t1/2 = Part B What fraction of the film will be left after 12 s? Assume thesame initial coverage as in part A.

Explanation / Answer

a ) Formula :                     t1/2 = a / 2k Where a is the initial amount            kis the rate constant             t1/2is the rate constant We have a =  8.9x1016molecules/cm2                k =   1.92x1013 molecules/cm2*s            t1/2=   8.9x1016molecules/cm2 / 2 * 1.92x1013molecules/cm2 *s                     =  2.3 x 103 s b) Formula :                   k = a / t                   at  = kt                        = 1.92x1013molecules/cm2 *s *12s                       = 23.04 x 10 13 molecules/cm2 Fraction left = 23.04 x 1013 molecules/cm2 / 8.9x1016molecules/cm2                        =  2.588x 10-3 Fraction left = 23.04 x 1013 molecules/cm2 / 8.9x1016molecules/cm2                        =  2.588x 10-3                       

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.