Using a multidiagnostic approach the rate Rev [ molec cm<sup>-3</sup> s<sup>-1</sup>] or flux J<sub>ev</sub> [ molec cm<sup>-2</sup> s<sup>-1</sup>] of evaporation of H<sub>2</sub>O and its corresponding rate constant for condensation, k<sub>cond</sub> [s<sup>-1</sup> ], on a 1 µm thick ice film have been studied in the temperature range 190 to 240 K as well as in the presence of small amounts of HCl and HBr that left the vapor pressure of H<sub>2</sub>O on ice unchanged. The resulting Arrhenius expressions for pure ice are J<sub>ev</sub> = 1.6 · 10 <sup>28 ± 1</sup> · exp (- 10.3 ± 1.2/ RT) [ molec cm<sup>-2</sup> s<sup>-1</sup>] , k<sub>cond</sub> = 1.7 · 10 <sup>- 2 ± 1</sup> · exp (+ 1.6 ± 1.5/ RT ) [s <sup>-1</sup>], in the presence of a HCl mole fraction in the range 3.2 · 10 <sup>- 5</sup> - 6.4 · 10 <sup>- 3</sup> : J<sub>ev</sub> = 6.4 · 10 <sup>26 ± 1</sup> · exp (- 9.7 ± 1.2/ RT) [ molec cm<sup>-2</sup> s<sup>-1</sup>] , k<sub>cond</sub> = 2.8 · 10 <sup>- 2 ± 1</sup> · exp ( + 1.5 ± 1.6 /RT) [s <sup>-1</sup>], and a HBr mole fraction smaller than 6.4 · 10 <sup>- 3</sup> : J<sub>ev</sub> = 7.4 · 10 <sup>25 ± 1</sup> · exp ( - 9.1 ± 1.2 /RT) [ molec cm<sup>-2</sup> s<sup>-1</sup>] , k<sub>cond</sub> = 7.1 · 10 <sup>- 5 ± 1</sup> · exp (+ 2.6 ± 1.5/ RT) [s <sup>-1</sup>]. The small negative activation energy for H<sub>2</sub>O condensation on ice points to a precursor mechanism. The corresponding enthalpy of sublimation is <font face="Symbol">D</font>H<sub>subl</sub> = E<sub>ev</sub> - E<sub>cond</sub> = 11.9 ± 2.7 kcal mol<sup>-1</sup> , <font face="Symbol">D</font>H<sub>subl</sub> = 11.2 ± 2.8 kcal mol<sup>-1</sup>, and <font face="Symbol">D</font>H<sub>subl</sub> = 11.7 ± 2.8 kcal mol<sup>-1</sup> whose values are identical within experimental uncertainty to the accepted literature value of 12.3 kcal mol<sup>-1</sup> . Interferometric data at 633 nm and FTIR absorption spectra in transmission support the kinetic results. The data are consistent with a significant lifetime enhancement for HCl- and HBr-contaminated ice particles by a factor of 3–6 and 10–20, respectively, for submonolayer coverages of HX once the fraction of the ice not contaminated by HX has evaporated.