The secondary bonding of gas molecules to a solid surface is a common mechanism
ID: 981025 • Letter: T
Question
The secondary bonding of gas molecules to a solid surface is a common mechanism for measuring the surface area of porous materials. By lowering the temperature of a solid well below room temperature, a measured volume of gas will condense to form a monolayer coating of molecules on the porous surface.
For a 110-g sample of fused copper catalyst, a volume of 8.9×103 mm3 of nitrogen (measured at standard temperature and pressure, 0 C and1 atm) is required to form a monolayer upon condensation. Calculate the surface area of the catalyst in units of m2/kg. (Take the area covered by a nitrogen molecule as 0.162 nm2 and recall that, for an ideal gas, pV=nRT, where n is the number of moles of the gas.)
Express your answer to three significant figures.
Explanation / Answer
PV=nRT
n=PV/RT
=2.42x1020molec.N2
Area covered= 39.2m2
or
S=392m2/Kg