Around `20%` surface sites have adsorbed `N_(2)`. On heating `N_(2)` gas evolved form sites and were collected at 0.001 atm and 298 K in a container of volume `2.46cm^(3)` the density of surface sites is `6.023xx10^(14)cm^(-2)` and surface area is `1000cm^(2)` find out the number of surface sites occupied per molecule of `N_(2)`.

Explanation

For adsorbed `N_2` on surface sites,`p(N_2) = 0.001` atm, `V = 2.46 cm^3`, T = 298 K, R = 82.0 atm `cm^3 K^(-1) mol^(-1)`
`n(N_2) = (pV)/(RT) = (0.001xx2.46)/(82.0xx298) = 1.006 xx 10^(-7)`
Molecuels of `N_2` adsorbed ` = 1.006 xx 10^(-7) xx 6.022 xx 10^23`
`=6.022 xx 10^16`
Total surface sites available = No.of sites per `cm^2 xx` Area
`=6.023 xx 10^14 xx 1000`
`=6.023 xx 10^17`
Surface sites on which `N_2` is adsorbed
`=(6.023 xx 10^17 xx 20)/100`
`=12.046 xx 10^16`
No. of sites adsorbed per molecules of `N_2`
`= (12.046xx 10^16)/(6.023 xx 10^16) =2`