1

### AIPMT 2006

A plot of log(x/m) versus log p for the adsorption of a gas on a solid gives a straight line with slope equal to
A
log K
B
$-$ log K
C
n
D
1/n

## Explanation

According to Freundlich adsorption isotherm, in the median range of pressure

${x \over m} \propto {P^{{1 \over n}}}$

$\Rightarrow$  ${x \over m}$ = kP$^{{1 \over n}}$

taking log both sides, we get,

log${x \over m}$ = logk + ${1 \over n}$ logP

Here in graph between log${x \over m}$ and logP, slope is ${1 \over n}$ and intercepts = log k.
2

### AIPMT 2005

Which one of the following forms micelles in aqueous solution above certain concentration?
A
Dodecyl trimethyl ammonium chloride
B
Glucose
C
Urea
D
Pyridinium chloride

## Explanation

Dodecyl trimethyl ammonium chloride is a cationic surfactant and forms micelles in aqueous solution above critical micelle concentration (CMC). 3

### AIPMT 2004

The enzyme which hydrolyses triglycerides to fatty acids and glycerol is called
A
maltase
B
lipase
C
zymase
D
pepsin

## Explanation

Triglycerides are lipids, hence these are hydrolysed by lipases to glycerol and fatty acids.
4

### AIPMT 2003

According to the adsorption theory of catalysis, the speed of the reaction increases because
A
the concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption
B
in the process of adsorption , the activation energy of the molecules becomes large
C
adsorption produces heat which increases the speed of the reaction
D
adsorption lowers the activation energy of the reaction.

## Explanation

The speed of the reaction increases because adsorption lowers the activation energy of the reaction.