### Certification Questions

Q:

The degree of dissociation ($α$) of a weak electrolyte, $AxBy$ is related to van't Hoff factor (i) by the expression:

$2.α=x+y-1i-1$

 A) 1 is correct B) 2 is correct C) 3 is correct D) 4 is correct

Explanation:

Van't Hoff factor (i) =

$AxBy1-α→xA+yxα+yB-xyα$

Total Moles = $1-α+xα+yα$ = $1-αx+y-1$

$i=1+αx+y-11$

$⇒α=i-1x+y-1$

Filed Under: Chemistry
Exam Prep: AIEEE

4 4766
Q:

Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of :

 A) An acetylenic triple bond B) Two ethylenic double bonds C) A vinyl group D) An isopropyl group

Explanation:

$C=}CH2→OzonolysisHCHO$

Vinylic group.

Filed Under: Chemistry
Exam Prep: AIEEE

1 3462
Q:

The structure of $IF7$ is

 A) Pentagonal bipyramid B) Square pyramid C) Trigonal bipyramid D) Octahedral

Explanation:

Hybridisation of iodine is $sp3d3$

So, the structure is pentagonal bipyramid.

Filed Under: Chemistry
Exam Prep: AIEEE

0 2356
Q:

The outer electron configuration of Gd (Atomic No : 64) is

1. $4f75d16s2$

2. $4f35d56s2$

3. $4f85d06s2$

4. $4f45d46s2$

Sol :

1. $4f75d16s2$

Subject: Chemistry Exam Prep: AIEEE

6582
Q:

Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at –6°C will be: (Kf  for water = 1.86 Kg/mol and molar mass of ethylene glycol = 62 kg/mol)

 A) 204.60 g B) 304.30 g C) 804.32 g D) 400.00 g

Explanation:

for ethylene glycol in aq. solution

=> w = 800 g

So, the weight of solute should be more than 800 g.

Filed Under: Chemistry
Exam Prep: AIEEE

4 5202
Q:

The magnetic moment (spin only) of  $[NiCl4]2-$is

 A) 1.41 BM B) 1.82 BM C) 5.46 BM D) 2.82 BM

Explanation:

Hybridisation of Ni is $e-$

Unpaired $3d8$in  is 2

So

Filed Under: Chemistry
Exam Prep: AIEEE

5 3361
Q:

In a certain city, 5% of all the persons in town have unlisted phone numbers. If you select 100 names at random from that city's phone directory, how many people selected will have unlisted phone numbers?

Zero. You are selecting names from the list, so they are all listed.

Subject: Math Puzzles

2660
Q:

I. Rural and semi-urban areas in the country have been suffering due to load shedding for quite some time.

II. If the Government is not able to overcome the power crisis, load shedding will be extended even to the urban areas.

 A) Statement I is the cause and statement II is its effect B) Statement II is the cause and statement I is its effect C) Both the statements I and II are effects of independent causes D) Both the statements I and II are effects of some common cause

Answer & Explanation Answer: D) Both the statements I and II are effects of some common cause

Explanation:

The facts given in both the statements are clearly the result of acute power shortage.