HARD
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The given graphs / data  I, II, III and IV represent general trends observed for different physisorption and chemisorption processes under mild conditions of temperature and pressure. Which of the following choice (s) about I, II, III and IV is (are) correct?

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Important Questions on Surface Chemistry

HARD
In an adsorption experiment, a graph between log x/m vs log P was fotund to be linear with a slope of 45o. The intercept on the log x/m axis was found to be 0.3. The amount of the gas adsorbed per gram of charcoal under a pressure of 1 atm is
MEDIUM
For Freundlich adsorption isotherm, a plot of log x/m y-axis and log px-axis gives a straight line, the intercept and slope fo rthe line is 0.4771 and 2, respectively. The mass of gas, adsorbed per gram of adsorbent if the initial pressure is 0.04 atm is _____  ×10-4g.
EASY
Which of the following graph is correctly represented according to Freundlich isotherm.
EASY

The curve that best describes the adsorption of a gas xg on 1.0 g of a solid substrate as a function of pressure p at a fixed temperature

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MEDIUM
Adsorption of a gas follows Freundlich adsorption isotherm. x is the mass of the gas adsorbed on mass m of the adsorbent. The plot of logxm vs  logp  is shown in the given graph. xm is proportional to,
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EASY

Freundlich adsorption isotherms for the physical adsorption of a gas at temperature T1, T2 and T3 are shown in the graph given below. The correct relationship between T1, T2 and T3 is

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EASY
Give an expression for Freundlich adsorptioin isotherm.
MEDIUM
The plot of logxm versus logp for the adsorption of a gas on a solid gives a straight line with slope equal to
EASY
A gas undergoes physical adsorption on a surface and follows the given Freundlich adsorption isotherm equation
xm=kp0.5
Adsorption of the gas increases with:
HARD

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

(Given log 3=0.4771)

MEDIUM

Consider the following statements about Langmuir isotherm.
I. The free gas and adsorbed gas are in dynamic equilibrium.
II. All adsorption sites are equivalent.
III. The initially adsorbed layer can act as a substrate for further adsorption.
IV. The ability of a molecule to get adsorbed at a given site is independent of the occupation of neighboring sites.

The correct statements are

EASY
Adsorption of gas on a surface follows Freundlich adsorption isotherm. The plot of logxm versus logP gives a straight line with slope equal to 0.5, then:

(xm is the mass of the gas adsorbed per gram of adsorbent)
MEDIUM

In Freundlich adsorption isotherm, slope of AB line is:

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EASY

If xm=kP1/n equation represents the Freundlich adsorption isotherm where x is the mass of the gas adsorbed on mass 'm' of the adsorbent at pressure P. k and n are constants which depend on the nature of adsorbent and the gas. Which of the following conditions represents the figure?

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EASY
The values of slope and intercept in the graph of Freundlich adsorption isotherm at 25°C temperature are 0.5 and 0.4771 respectively. What will be the proportion of adsorption at 4 bar pressure?
EASY
Under what condition, will x/m value be equal to pressure of the gas on the surface of the absorbent?
MEDIUM

CO2 gas adsorbs on charcoal following Freundlich adsorption isotherm. For a given amount of charcoal, the mass of CO2 adsorbed becomes 64 times when the pressure of CO2 is doubled.

The value of n in the Freundlich isotherm equation is ____ ×102. (Round off to the Nearest Integer)

EASY
Adsorption of a gas follows Freudlich adsorption isotherm. If x is the mass of the gas adsorbed on mass m of the adsorbent, the correct plot of xm versus p is:
MEDIUM
For a linear plot of log xm versus log p in a Freundlich adsorption isotherm, which of the following statements is correct? (k and n are constants)
MEDIUM
3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06 N) in a flask. After an hour, it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is: