Thermochemistry is not a lower bound to the activation energy of endothermic reactions: A kinetic study of the gas-phase reaction of atomic chlorine with ammonia

PDF Version Also Available for Download.

Description

Article on a kinetic study of the gas-phase reaction of atomic chlorine with ammonia.

Physical Description

7 p.

Creation Information

Gao, Yide; Alecu, I. M.; Hsieh, P-C; Morgan, Brad P.; Marshall, Paul & Krasnoperov, Lev N. March 9, 2006.

Context

This article is part of the collection entitled: UNT Scholarly Works and was provided by UNT College of Arts and Sciences to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 20 times . More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Authors

Publisher

Provided By

UNT College of Arts and Sciences

The UNT College of Arts and Sciences educates students in traditional liberal arts, performing arts, sciences, professional, and technical academic programs. In addition to its departments, the college includes academic centers, institutes, programs, and offices providing diverse courses of study.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Degree Information

Description

Article on a kinetic study of the gas-phase reaction of atomic chlorine with ammonia.

Physical Description

7 p.

Notes

Abstract: The rate constant for Cl + NH3 → HCl + NH2 has been measured over 290−570 K by the time-resolved resonance fluorescence technique. Ground-state Cl atoms were generated by 193 nm excimer laser photolysis of CCl4 and reacted under pseudo-first-order conditions with excess NH3. The forward rate constant was fit by the expression k1 = (1.08 ± 0.05) × 10-11 exp(−11.47 ± 0.16 kJ mol-1/RT) cm3 molecule-1 s-1, where the uncertainties in the Arrhenius parameters are ±1 σ and the 95% confidence limits for k1 are ±11%. To rationalize the activation energy, which is 7.4 kJ mol-1 below the endothermicity in the middle of the 1/T range, the potential energy surface was characterized with MPWB1K/6-31++G(2df,2p) theory. The products NH2 + HCl form a hydrogen-bonded adduct, separated from Cl + NH3 by a transition state lower in energy than the products. The rate constant for the reverse process k-1 was derived via modified transition state theory, and the computed k-1 exhibits a negative activation energy, which in combination with the experimental equilibrium constant yields k1 in fair accord with experiment.

Reprinted with permission from the Journal of Physical Chemistry A. Copyright 2006 American Chemical Society.

Source

  • Journal of Physical Chemistry A, 2006, Washington D.C.: American Chemical Society, pp. 6844-6850

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

Publication Information

  • Publication Title: Journal of Physical Chemistry A
  • Volume: 110
  • Issue: 21
  • Page Start: 6844
  • Page End: 6850
  • Pages: 7
  • Peer Reviewed: Yes

Collections

This article is part of the following collection of related materials.

UNT Scholarly Works

Materials from the UNT community's research, creative, and scholarly activities and UNT's Open Access Repository. Access to some items in this collection may be restricted.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • March 9, 2006

Added to The UNT Digital Library

  • March 17, 2015, 10:38 a.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 20

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Gao, Yide; Alecu, I. M.; Hsieh, P-C; Morgan, Brad P.; Marshall, Paul & Krasnoperov, Lev N. Thermochemistry is not a lower bound to the activation energy of endothermic reactions: A kinetic study of the gas-phase reaction of atomic chlorine with ammonia, article, March 9, 2006; [Washington, D.C.]. (digital.library.unt.edu/ark:/67531/metadc501422/: accessed December 15, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT College of Arts and Sciences.