Question

The mass of gas adsorbed, x per unit mass of adsorbed, m was measured at various x pressures p. A graph between `log  "x"/"m"` and log p gives a straight line with slope equal to 2 and the intercept equal to 0.4771. The value of `"x"/"m"` at a pressure of 4 atm is ______.

[Given log 3 = 0.4771]

Options

• 2

• 4

• 6

• 8

Answer 1

The mass of gas adsorbed, x per unit mass of adsorbed, m was measured at various x pressures p. A graph between `log  "x"/"m"` and log p gives a straight line with slope equal to 2 and the intercept equal to 0.4771. The value of `"x"/"m"` at a pressure of 4 atm is 6.

Explanation:

From Freundlich's adsorption isotherms equation

We get,

`"x"/"m" = "Kp"^(1//"n")`

⇒ `log("x"/"n") = log "k" + 1/"n" log "p"`

Here slope = `1/"n"` = 2

Intercept = log K = 0.4771

∴ K = Antilog 0.4771 = 3

∴ n = `1/2`

∴ `"x"/"m" = 3 xx (4)^(1//2)` = 6