18. 0.004 M is isotonic with 0.01 M glucose. Degree of dissociation of is

a) 75% b) 50%

c) 25% d) 85%

Ans:a. 

or

i = 2.5

or75% dissociation

19. and . Find temperature of vapour, at one atmosphere

a) 400K b) 350 K

c) 298 K d) 250 K

Ans:a. 

At equilibrium

20. 2 mol of an ideal gas expanded isothermally & reversibly from 1 litres at 300 K. What is the enthalpy change ?

a) 4.98 KJ b) 11.47 KJ

c) -11.47 KJ d) 0 KJ

Ans:d. 

H = E + PV

and

or

21. (A) follows first order reaction. . Concentration of A, changes from 0.1 M to 0.025 M in 40 minutes. Find the rate of reaction of A when concentration of A is 0.01 M

a)

b)

c)

d)

Ans:a.

Cocentration changes from 0.01 to 0.025 M in minutes

22. 2-hexyne gives trans-2-hexene on treatment with

a) b)

c) d)

Ans: a. brings about trans addition of

23. How many chiral compounds are possible on mono chlorination of 2-methyl butane ?

a) 2 b) 4

c) 6 d) 8

Ans:b.

24. Which of the following pairs gives positive Tollen's test ?

a) Glucose, sucrose

b) Glucose, fructose

c) Hexanal, Acetophenone

d) Fructose, sucrose

Ans:b. 
Aldehydes and -hydroxy ketones give positive Tollen's test. Glucose has an alddehydic group and fructose is an hydroxy ketone

25. Which of the following has —O—O—linkage

a) b)

c) d)

Ans:b.

26. When is oxidised by in alkaline medium converts into

a) b)

c) d)

Ans:a.

 

27. Number of lone(s) in is /are

a) 0 b) 1

c) 2 d) 3

Ans:b. 

Structure of

Number of lone pairs on the central atom is1

28. According to MO Theory,

a) is paramagnetic and bond order greater than

b) is paramagnetic and bond order less than

c) is diamagnetic and bond order less than

d) is diamagnetic and bond order more than

Ans:a.

[no. of bonding - no. of antibonding electrons]

One unpaired hence paramagnetic