Q5(b)(ii). Time to form half a monolayer at 2.0 × 10⁻¹¹ torr
How long will it take for about one-half of a monolayer to form on the surface if the surface is exposed to a pressure of 2.0 × 10⁻¹¹ torr? Assume that monolayer formation needs an exposure of 1 Langmuir. Also give the reason for using such a low pressure in cleaning the surface.
Answer in brief
t = 0.5 × 10⁻⁶ torr s / 2.0 × 10⁻¹¹ torr = 2.5 × 10⁴ s, about 6.9 hours.
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CoversLangmuir exposuremonolayerultra-high vacuumsurface collision rateadsorption
All parts of Question 5
- 5(a) Fluorescence and phosphorescence on a Jablonski diagram10 marks
- 5(b)(i) How water condenses onto glass5 marks
- 5(b)(ii) Time to form half a monolayer at 2.0 × 10⁻¹¹ torr5 marks
- 5(c) IUPAC names of five complexes10 marks
- 5(d) Zeise's salt: synthesis and structure10 marks
- 5(e)(i) Lanthanide contraction5 marks
- 5(e)(ii) Why Hf is placed below Zr5 marks