Question

20% surface sites have adsorbed N₂. On heating N₂ gas evolved from sites and were collected at 0.001 atm and 298 K in a container of volume is 2.46 cm³. Density of surface sites is 6.023 × 10¹⁴/cm² and surface area is 1000 cm², the no. of surface sites occupied per molecule of N₂ is ______.

Options

• 1

• 2

• 3

• 4

Answer 1

20% surface sites have adsorbed N₂. On heating N₂ gas evolved from sites and were collected at 0.001 atm and 298 K in a container of volume is 2.46 cm³. Density of surface sites is 6.023 × 10¹⁴/cm² and surface area is 1000 cm², the no. of surface sites occupied per molecule of N₂ is 2.

Explanation:

`"n"_("N"_2) = "PV"/"RT"`

= `(0.001 × 2.46)/(1000 × 0.08 × 298)`

= `(0.001 × 2.46)/(1000 × 24.4)`

= 10^–7 mole

= 60 × 10²³ × 10^–7

= 6 × 10¹⁶

Total surface sites = 6.023 × 10¹⁷

= `(0.2 × 6 × 10^17)/(6 × 10^16)`

= 2