Factors Affecting Adsorption

Q.

Which is heavier Nitrogen or air?

Q. During adsorption, there is a decrease in surface energy which appears as heat.

1. True
2. False

Q. There were many gas molecules $N{H}_3,CO,C{H}_4$ and $S{O}_2$ in a group once. They were discussing about who would be the better adsorbate on charcoal. So, they decided to have race among themselves to prove it as to who would be adsorbed more in the same time.
Who do you think won?

1. CO
2. $N{H}_3$
3. $C{H}_4$
4. $S{O}_2$

Q. Which of the following gases are most easily adsorbed on a solid surface?
Gas $S{O}_2$ $C{H}_4$ $N_2$ $H_2$

$T_c$ 330 K 190 K 126 K 33 K

1. $S{O}_2$
2. $C{H}_4$
3. $H_2$
4. $N_2$

Q.

For adsorption of a gas:

1. $\Delta H<0,\Delta S<0$

2. $\Delta H<0,\Delta S>0$

3. $\Delta H>0,\Delta S>0$

4. $\Delta H=0,\Delta S>0$

Q. 50 ml of 1 M oxalic acid is shaken with 0.5 gm of wood charcoal. The final concentration of the solution after adsorption is 0.2 M. Amount of oxalic acid absorbed per gm of charcoal is (Use molar mass of hydrated oxalic acid = 126)

1. 2.52 gm
2. 6.30 gm
3. 10.08 gm
4. None

Q. Which of the following gases are most easily adsorbed on a solid surface?
Gas $S{O}_2$ $C{H}_4$ $N_2$ $H_2$

$T_c$ 330 K 190 K 126 K 33 K

1. $S{O}_2$
2. $C{H}_4$
3. $H_2$
4. $N_2$

Q. Which among the following statement is false?
A. Chemisorption is reversible in nature
B. Particle size of adsorbent will not affect the amount of adsorption
C. Increase of pressure increases amount of adsorption
D. Increase of temperature always decreases the amount of adsorption

1. A, D
2. A, B, D
3. A
4. All are false

Q.

The volume of gases $N{H}_3$, $C{O}_2$ and $C{H}_4$ adsorbed by one gram of charcoal at 298 K are in

1. $C{H}_4>CO2>N{H}_3$

2. $N{H}_3>C{H}_4>C{O}_2$

3. $N{H}_3>C{O}_2>C{H}_4$

4. $C{O}_2>N{H}_3>C{H}_4$

Q.

Which statement is/are correct?

i) Physical adsorption is due to Van der Waal's forces

ii) Physical adsorption decreases at high temperature

iii) Physical adsorption is irreversible

iv) Enthalpy for a chemical adsorption is generally lesser than that of physical adsorption

1. i, ii &iv

2. i, ii & iii

3. i, ii

4. i&iv

Q.

The volume of gases $N{H}_3$, $C{O}_2$ and $C{H}_4$ adsorbed by one gram of charcoal at 298 K are in

1. $C{H}_4>CO2>N{H}_3$

2. $N{H}_3>C{H}_4>C{O}_2$

3. $N{H}_3>C{O}_2>C{H}_4$

4. $C{O}_2>N{H}_3>C{H}_4$

Q.

The volumes of gases $H_2,C{H}_4,C{O}_{2}andN{H}_3$ absorbed by 1 g of charcoal at 288 K are in the order:

1. $H_2>C{H}_4>C{O}_2>N{H}_3$

2. $C{H}_4>C{O}_2>N{H}_3>H_2$

3. $CO2>N{H}_3>H_2>C{H}_4$

4. $N{H}_3>C{O}_2>C{H}_4>H_2$

Q. 50 mL of 1 M oxalic acid (molar mass$=126{\text{gmol}}^{-1}$) is shaken with 0.5 g of wood charcoal. The final concentration of the solution after adsorption is 0.5 M. The amount of oxalic acid (in grams) adsorbed per gram of the charcoal is:

1. 3.15
2. 1.575
3. 12.6
4. 6.3

Q.

Which gas is strongly adsorbed by charcoal -

1. CO

2. $N_2$

3. $H_2$

4. $N{H}_3$

Q. Which of the following is not true about adsorption of gases on solids?

1. As the critical temperature ($T_c$) of a gas increases, it becomes more difficult to liquify it and easier to adsorb it on to a solid
2. To increase the adsorbing power of an adsorbent, they are sub-divided into smaller pieces. The surface area increases, and the adsorbing power increases
3. The extent of adsorption of a gas per unit mass of the adsorbent depends on the pressure of the gas
4. Physical adsorption decreases continuously with an increase in the temperature

Q. Which of the following statements are false?
A. Freundlich adsorption isotherm holds good for all pressure ranges.
B. The force of attraction existing between the adsorbate and adsorbent are Vander Waal’s forces in case of chemisorption.
C. Adsorption is an endothermic process.
D. The extent of adsorption decreases with increase in temperature for a physiosorption process.

1. B, C, D
2. A, B, C
3. B, C
4. All are false

Q. Which of the following statements are false?
A. Freundlich adsorption isotherm holds good for all pressure ranges.
B. The force of attraction existing between the adsorbate and adsorbent are Vander Waal’s forces in case of chemisorption.
C. Adsorption is an endothermic process.
D. The extent of adsorption decreases with increase in temperature for a physiosorption process.

1. B, C, D
2. A, B, C
3. B, C
4. All are false

Q. There were many gas molecules $N{H}_3,CO,C{H}_4$ and $S{O}_2$ in a group once. They were discussing about who would be the better adsorbate on charcoal. So, they decided to have race among themselves to prove it as to who would be adsorbed more in the same time.
Who do you think won?

1. CO
2. $N{H}_3$
3. $C{H}_4$
4. $S{O}_2$

Q.

Oxygen can be liquefied into a bluish liquid at _____$°\mathrm{C}$ by applying high pressure.

1. $-183$

2. $-182$

3. $-173$

4. $-184$