Surface Chemistry · Question 16

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

1. Enzymes are mostly proteinous in nature.
2. Enzyme action is specific.
3. Enzymes are denatured by ultraviolet rays and at high temperature.
4. Enzymes are least reactive at optimum temperature.

The protecting power of lyophilic colloidal sol is expressed in terms of

1. coagulation value
2. gold number
3. critical micelle concentration
4. oxidation number

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

1. x/m = f(p) at constant T
2. x/m = f(T) at constant p
3. p = f(T) at constant (x/m)
4. xm = p T

The Langmuir adsorption isotherm is deduced using the assumption

1. the adsorption sites are equivalent in their ability to adsorb the particles
2. the heat of adsorption varies with coverage
3. the adsorbed molecules interact with each other
4. the adsorption takes place in multilayers

A plot of (x/m) versus p for the adsorption of a gas on a solid gives a straight line with slope equal to

1. K
2. - K
3. n
4. 1/n

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

1. Dodecyl trimethyl ammonium chloride
2. Glucose
3. Urea
4. Pyridinium chloride

Which of the following forms cationic micelles above certain concentration?

1. Sodium dodecyl sulphate
2. Sodium acetate
3. Urea
4. Cetyltrimethylammonium bromide.

According to the adsorption theory of catalysis, the speed of the reaction increases because

1. the concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption
2. in the process of adsorption, the activation energy of the molecules becomes large
3. adsorption produces heat which increases the speed of the reaction
4. adsorption lowers the activation energy of the reaction.

Position of non-polar and polar part in micelle

1. polar at outer surface but non-polar at inner surface
2. polar at inner surface but non-polar at outer surface
3. distributed over all the surface
4. are present in the surface only

Which is not correct regarding the adsorption of a gas on surface of a solid?

1. On increasing temperature adsorption increases continuously.
2. Enthalpy and entropy change is negative.
3. Adsorption is more for some specific substance.
4. It is a reversible reaction.