Top 54 questions for the Net/Gate/IIT Jam/TIFR/M.sc entrance MCQ chemistry

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 1

 Answer: B

 Solution: 

 The relationship between these following compounds is ______.

 Answer: C

Answer:

B

 Solution:

  For the concentration cell, 

Answer: A

 Solution:

 Answer: D

 Solution:

 Let us consider the following consecutive reaction:

  The relationship between these following compounds is ______.

 Answer: A

 Solution:

 Answer:

 C

Solution:

  Among the following, the most stable isomer for 3-methoxycyhexanol is

 Answer: A

 Solution:

 Identify two enantiomers among the following compounds.

 Answer:  4

 Solution:

C & D are mirror image of each & non-superimposable.  That's enantiomers.

 The value of the rate constant for gas phase reaction, 2 NO₂ + F₂ → 2NO₂F is 38 dm³.mol–¹.s–¹ at 300K.

 The order of the reaction is _____.

Answer: C

 Solution:

 Answer:

 D

 Solution:

 A cup of water at 278 K (the system) is placed in a microwave oven and the oven is turned on for one minute, during which it begins to boil. 

For the above case:

A) q= negative

B)   W =0

C) ∆U= positive

D) A & C

 Answer: C

 Solution:

 In which of the following mixtures of solvents will there be intermolecular hydrogen bonding between the different solvent molecules?

 Select the correct option:

 Answer: 

 D

 Solution:

 The solid-state structure of BeCl₂ is

A:
B:
C:
D:	none

 Answer:

 C

 Solution:

BeCl₂ dimerizes to a 3-coordinate structure in the vapor phase, but the linear monomer is formed at high temperatures. 

 Which one of the following molecules will have n→π* transition at the longest wavelength?

 Answer:

 C

 Solution:

 Among the following isomers of C₄H₆ given below, the compound which exhibits an absorption band at 3300 cm^-1 in the IR spectrum, is 

 Answer:

 B

Solution:

 Match the compound in list I with the stretching frequencies (cm^-1) of the principal functional groups given in list II.

 Answer:

 C

Solution:

 Answer:

 A

 Solution:

 Answer:

 D

 Solution:

 Anhydride > ketone > amide

 Answer:

B

 Solution:

 Answer: B 

Solution:

 Answer:

 B

 Solution:

 Answer:

 D

 Solution:

 Answer:

 C

 Solution:

 Among the following molecules, which contains covalent bond between two atoms of same kind?

 Answer:

 D

Solution:

 There is no S-S bond in

 Answer:

C

Solution:

 The no of hydroxyl(-OH) present in phosphorous acid is 

 Answer:

2

Solution

 Among the oxides of nitrogen, which have N-N bond ?

 Answer:

D

Solution:

 Answer:

A

Solution:

 The species in which the N-atom is in a state of sp hybridisation is 

Answer:

d

Solution:

  Answer:

 B

Solution:

 Answer:

 D

 Solution:

 The number of P-O-P bonds in cyclic metaphosphoric acid is 

A) 0

B) 2

C) 3

D) 4

 Answer:

C

Solution:

 Answer:

B

 Solution:

 What will be the final product?

 Select the correct option:

 Answer:

 b

Solution:

 What will be the final product?

 Select the correct option:

Answer:

b

Solution:

B is _______.

Select the correct option:

 Answer:

c

Solution:

 Select the correct option:

Answer:

 d

Solution:

 Select the correct option:

 Answer:

d

Solution:

 Select the correct option:

 Answer:

a

Solution:

 Select the correct option:

 Answer:

 a

Solution:

 Select the correct option:

 Answer:

a

Solution:

 Select the correct option:

 Answer:

a

Solution:

 Select the correct option:

 Answer:

  A

 Solution:

 Hence,

  √ [n(n+2)] = 4

or, [n(n+2)] = 16 ≈ 15

or, n² + 2n = 15

or, n² + 5n - 3n -15 = 0

or, n(n+5) - 3(n+5) = 0

or, n = 3 [n = -5, it is not acceptable]

Hence, the octahedral Co(+2) complex contains 3 unpaired electrons. This condition is satisfied by the electronic configuration denoted by 1,3 & 4.

Hence, the electronic configuration of the complex is :  t_2g ⁵e_g²

 The correct order of reducing power of the following hydrides _____.

 Select the correct option:

Answer:

 B

 Solution:

  Reducing power of a hydride depends on the M-H bond strength.

 Greater is the M-H bond strength, lower will be the chance of getting hydride ion (H^-) & hence, lower will be the reducing power of the hydride. Among B, Al & Ga the size increases from B to Ga. 'H' atom is smaller in size. Better orbital overlap will occur between two orbitals of similar size. 

As size increase from B to Ga, M-H bond strength will decrease from B-H to Ga-H.

 Hence,  [BH₄]^- will give up H^- least willingly while [GaH₄]^- will give up H^- with most readily.

 Hence, the reducing power of the given hydrides run as : 3>2>1

Hence, the correct answer is : B.

 Which of the following parameters can't be estimated by using Born-Haber Cycle in case of NaCl?

e

 Select the correct option:

 Answer:

 D

 Solution:

  The Born-Haber Cycle for NaCl crystal formation from its constituent elements is as follows:

 Hence, from Born-Haber Cycle, it is clear that no electronegativity terms is involved in the equation.

Hence, electronegativity cannot be estimated by using Born-Haber Cycle.

 Hence the correct answer is : D

 An electron travels with a velocity of 'v' ms-1. For a proton to have the same de-Broglie wavelength, the velocity will be approximately:

  A

 Solution:

 According to de-Broglie, the wavelength of an electron moving with velocity v ms-1 is given by: 

 The compound [Cr(H₂O)₆]Cl₃ &[Cr(H₂O)₄Cl₂]Cl(H₂O)₂ represent ____.

 Select the correct option:

 B

 Solution:

 Ionization isomers are coordination compounds that have 2 two different ligands swapped between the inner and the outer coordination spheres. If one of the ligands are water, that type of isomerism is known as Hydrate isomerism.

 In the given example two water ligands from the inner coordination sphere are exchanged with the two chloride ligands present at the outer coordination sphere.

 Hence, it is an example of Hydrate isomerism.

 Hence, the correct answer is : B.

If 'a' is its edge length, then which of the following expressions is correct?

 Select the correct option:

 Answer:

 A

Solution:

So, the correct answer is A.

The rate of physisorption increase with _____________.

 Select the correct option:

Answer:

 A

Solution:

  The reduction of but-2-yne to trans-but-2-ene can be bought about by_____.

Select the correct option:

 Answer:

 B

Solution:

 Select the correct option:

 Answer:

 B

Solution:

 The ionic strength of 0.1 M aqueous solution of Fe₂(SO₄)₃ is _______.

Select the correct option:

  Answer:

 D

Solution: