# When the Langmuir equation is used to measure the surface area of a solid, S, (m2/g) it is assumed..

When the Langmuir equation is used to measure the surface area of a solid, S, (m2/g) it is assumed that the area occupied by a molecule of the adsorbing gas (nitrogen) at its normal boiling point (-196 “C) is 0.162 nm2. Show that S, = 4.35 V, where V, is the volume corresponding to a monolayer of gas. [ V, is usually corrected to standard temperature and pressure (i.e. 1 atm and 0 “C) (Allen (1997) Vol. 2 p. 44).]