Chemisorption

Q.

State true or false: Chemisorption is irreversible.

1. True
2. False

Q.

1 g charcoal adsorbs 100 ml of 0.5 M $C{H}_{3}CHOOH$ to form a monolayer. As a result molarity of acetic acid reduces to 0.49 M. What will be the surface area covered by each molecule of acetic acid? Given that surface area of charcoal $=3.01\times {10}^2{m}^2/g$.

1. $2.5\times {10}^{-19}{m}^2$

2. $5.0\times {10}^{-19}{m}^2$

3. ${10}^{-18}{m}^2$

4. $2.0\times {10}^{-18}{m}^2$

Q. When dioxygen is adsorbed on a metallic surface, the electron transfer occurs from the metal to the molecule. The true statements regarding this adsorption are:

1. $O_2$ is physisorbed
2. Heat is released
3. Occupancy of ${\pi }_{2px}^{\ast }$ $O_2$ is increased
4. Bond length of $O_2$ is increased

Q.

The correct statement(s) pertaining to the adsorption of a gas on a solid surface is (are)

1. Adsorption is always exothermic.

2. Physisorption may transformation into chemisorption at high temperature.

3. Physisorption increases with increasing temperature but chemisorption decreases with increasing temperature.

4. Chemisorption is more exothermic than physisorption; however, it is very slow due to higher energy of activation.

Q.

The rate of chemisorption :

1. decreases with increase of pressure
2. increases with increase of pressure
3. is independent of pressure
4. is independent of temperature