Surface Chemistry

Surface Chemistry
Class:XII / Unit:5

Which one of the following statement is incorrect about enzyme catalysis?

Enzymes are denaturated by ultraviolet rays and at high temperature
Enzyme action is specific
Enzymes are least reactive at optimum temperature
Enzymes are mostly proteinous in nature

In Freundlich Adsorption Isotherm, the value of 1/n is

1 in case of physical adsorption
1 in case of chemisorption
Between 0 and 1 in all cases
Between 2 and 4 in all cases

Rate of Physical Adsorption increase with

increase in temperature
decrease in temperature
decrease in pressure
decrease in surface area

Which one of the followings forms micelles in aqueous solution above certain concentration?

Pyridinium chloride
Dodecyl trimethyl ammonium chloride
Glucose
urea

A plot of log x/m vs log p for adsorption of gas on a solid gives in straight line with slope equal to

-log K
log K
n
1/n

The formation of micelles takes place only above

Kraft temperature
Critical temperature
Boyle’s temperature
Inversion temperature

Lyophillic colloids are stable due to

charge on the particles
layer of dispersion of medium on the particles
small size of the particles
large size of the particles

If x is amount of adsorbate and m is the amount of adsorbent, which of the following relations is not related to adsorption process ?

x/m = f(T) at constant p
x/m = p × T
x/m = f(p) at constant T
p = f(T) at constant (x/m)

From which of the following effect colloidal system is free ?

Concentration of electrolyte
Applied electrical field
Gravitational
Heat

The movement of colloidal particles towards the oppositely charged electrodes on passing electric current is known as

Cataphoresis
Brownian movement
Tyndall effect
None of these