Example 3 From the isotherm below determine the specific por

Example 3: From the isotherm below determine the specific pore volume. The density of nitrogen gas is 1.25x10-3 g cm-3 and the molar volume of liquid nitrogen is 34.7 cm3 mol-1 600 Active carbon N2 adsorption isotherm 500 400 From maximal volume adsorbed, find mass of adsorbed gas, then number of moles and then number of moles multiply by molar volume of liquid nitrogen to find the specifie pore volun 300 100 0.0 0.2 0.4 06 0.8 Relat ve Pressure

Solution

Density = mass/volume

Therefore mass of gas= density×volume

Mass= 1.25×10^-3 ×34.7

Mass of gas= 0.0433grams

Now moles of nitrogen gas= weight in grams/molecular weight

Moles= 0.0433/28

Moles of nitrogen=1.2145

Specific volume= molar volume× moles of nitrogen

=34.7×10^-6 ×1.2145

=4.2143×10^-7 m^3mol

Here 34.7cm^3 is converted into m^3