Chemistry

The correct order of bond angles (smallest first) in H2S, NH3, BF3 and SiH4 is

  1. H2S < NH3 < SiH4 < BF3
  2. NH3 < H2S < SiH4 < BF3
  3. H2S < SiH4 < NH3 < BF3
  4. H2S < NH3 < BF3 < SiH4

The bond order in NO is 2.5 while that in NO+ is 3. Which of the following statements is true for these two species?

  1. Bond length is unpredictable
  2. Bond length in NO+ is equal to that in NO
  3. Bond length in NO+ is greater than in NO
  4. Bond length in NO is greater than in NO+

The molecule having smallest bond angle is

  1. AsCl3
  2. PCl3
  3. SbCl3
  4. NCl3

A square planar complex is formed by hybridisation of which atomic orbitals?

  1. s, px, py, pz
  2. s, px, py, pz, d
  3. d, s, px, py
  4. s, px, py, pz, d, d

In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following interorbit jumps of the electron for Bohr orbits in an atom of hydrogen?

  1. 2 → 5
  2. 4 → 1
  3. 5 → 2
  4. 3 → 2

Which of the following sets of quantum numbers is correct for an electron in 4f orbital?

  1. n = 4, l = 4, m = –4, s =-1/2
  2. n = 4, l = 3, m = +4, s =+1/2
  3. n = 3, l = 2, m = –2, s =+1/2
  4. n = 4, l = 3, m = +1, s =+1/2

Which of the following statements in relation to the hydrogen atom is correct?

  1. 3s orbital is lower in energy than 3p orbital
  2. 3s, 3p and 3d orbitals all have the same energy
  3. 3s and 3p orbitals are of lower energy than 3d orbital
  4. 3p orbital is lower in energy than 3d orbital

Consider the following nuclear reactions:

23892M → XYN + 242He  ;  XYN → ABL + 2β+

The number of neutrons in the element L is

  1. 146
  2. 144
  3. 142
  4. 140

How many moles of magnesium phosphate, Mg3(PO4)2 will contain 0.25 mole of oxygen atoms?

  1. 2.5 x 10-2
  2. 0.02
  3. 1.25 x 10-2
  4. 3.125 x 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

  1. decrease twice
  2. remain unchanged
  3. increase two fold
  4. be a function of the molecular mass of the substance

With increase of temperature, which of these changes?

  1. molality
  2. molarity
  3. mole fraction
  4. weight fraction of solute

What volume of hydrogen gas, at 273 K and 1 atm. pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?

  1. 89.6 L
  2. 67.2 L
  3. 44.8 L
  4. 22.4 L

Number of atoms in 558.5 gram Fe (atomic weight of Fe = 55.85 g mol–1) is

  1. twice that in 60 g carbon
  2. 558.5 × 6.023 × 1023
  3. half that in 8 g He
  4. 6.023 × 1022

In the reaction,

2Al (s) + 6HCl (aq) → 2Al3+ (aq) + 6Cl (aq) + 3H2 (g)

  1. 6 L HCl (aq) is consumed for every 3 L H2(g) produced
  2. 11.2 L H2(g) at STP is produced for every mole HCl (aq) consumed
  3. 33.6 L H2(g) is produced regardless of temperature and pressure for every mole Al that reacts
  4. 67.2 L H2(g) at STP is produced for every mole Al that reacts

The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SO3Na (Mol. Wt. 206). What would be the maximum uptake of Ca2+ ions by the resin when expressed in mole per gram resin?

  1. 2/309
  2. 1/103
  3. 1/206
  4. 1/412

Which of the following is the energy of a possible excited state of hydrogen?

  1. - 6.8 eV
  2. - 3.4 eV
  3. + 6.8 eV
  4. + 13.6 eV

The ionic radii (in Å) of N3–, O2– and F are respectively

  1. 1.36, 1.71 and 1.40
  2. 1.71, 1.40 and 1.36
  3. 1.71, 1.36 and 1.40
  4. 1.36, 1.40 and 1.71

The color of KMnO4 is due to

  1. d – d transition
  2. L → M charge transfer transition
  3. σ – σ* transition
  4. M → L charge transfer transition

Which of the following compounds is not an antacid?

  1. Cimetidine
  2. Phenelzine 
  3. Ranitidine
  4. Aluminium hydroxide

In the context of the Hall-Heroult process for the extraction of Al, which of the following statements is false?

  1. Al2O3 is mixed with CaF2 which lowers the melting point of the mixture and brings conductivity
  2. Al3+ is reduced at the cathode to form Al
  3. Na3AlF6 serves as the electrolyte
  4. CO and CO2 are produced in this process

Which polymer is used in the manufacture of paints and lacquers?

  1. Glyptal
  2. Polypropene
  3. Poly vinyl chloride
  4. Bakelite

In a compound C, H and N atoms are present in 9:1:3.5 by weight. Molecular weight of compound is 108. Molecular formula of compound is

  1. C9H12N3
  2. C3H4N
  3. C6H8N2
  4. C2H6N2

Number of atoms in 558.5 gram Fe (atomic weight of Fe = 55.85 g mol–1) is

  1. twice that in 60 g carbon
  2. half that in 8 g He
  3. 6.023 × 1022
  4. 558.5 × 6.023 × 1023

The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 metres per second is approximately (Planck's constant, h = 6.63 × 10–34 Js)

  1. 10–16 metres
  2. 10–31 metres
  3. 10–33 metres
  4. 10–25 metres

Which one of the following compounds has the smallest bond angle in its molecule?

  1. NH3
  2. SH2
  3. SO2
  4. OH2

For an ideal gas, number of moles per litre in terms of its pressure P, gas constant R and temperature T is

  1. P/RT
  2. PT/R
  3. RT/P
  4. PRT

The enthalpy change for a reaction does not depend upon the

  1. use of different reactants for the same product.
  2. nature of intermediate reaction steps.
  3. physical states of reactants and products.
  4. difference in initial or final temperatures of involved substances.

Butene-­1 may be converted to butane by reaction with

  1. Zn-Hg
  2. Sn-HCl
  3. Zn-­HCl
  4. Pd/H2

On mixing a certain alkane with chlorine and irradiating it with ultraviolet light, it forms only one monochloroalkane. This alkane could be

  1. neopentane
  2. pentane
  3. propane
  4. isopentane

2-­Methylbutane on reacting with bromine in the presence of sunlight gives mainly

  1. 2-­bromo­-2-­methylbutane
  2. 1-­bromo-­3-­methylbutane
  3. 2-­bromo-­3-­methylbutane
  4. 1-­bromo-­2-­methylbutane

Presence of a nitro group in a benzene ring

  1. deactivates the ring towards nucleophilic substitution
  2. activates the ring towards electrophilic substitution
  3. renders the ring basic
  4. deactivates the ring towards electrophilic substitution

The reaction of toluene with Cl2 in presence of FeCl3 gives predominantly

  1. benzoyl chloride
  2. m-­chlorobenzene
  3. benzyl chloride
  4. o­- and p­-chlorotoluene

Which of the following reactions will yield 2, 2-­dibromopropane?

  1. C2H2 + 2HBr →
  2. CH3CHCH2 + 2HBr →
  3. CH3CHCHBr + HBr →
  4. CH3CCH + 2HBr →

The hydrocarbon which can react with sodium in liquid ammonia is

  1. CH3CHCHCH3
  2. CH3CH2C≡CCH2CH3
  3. CH3CH2CH2C≡CCH2CH2CH3
  4. CH3CH2C≡CH

The alkene that exhibits geometrical isomerism is

  1. 2-methyl propene
  2. 2 methyl 2 butene
  3. 2-Butene
  4. propene

The IUPAC name of neopentane is

  1. 2 – methylpropane
  2. 2, 2 – dimethylpropane
  3. 2 – methylbutane
  4. 2, 2 – dimethylbutane

One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is

  1. 1-butene
  2. 2-butene
  3. propene
  4. ethene

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

  1. an acetylenic triple bond
  2. a vinyl group
  3. two ethylenic double bonds
  4. an isopropyl group

Alkyl halides react with dialkyl copper reagents to give

  1. alkenes
  2. alkenyl halides
  3. alkanes
  4. alkyl copper halides

During dehydration of alcohols to alkenes by heating with concentrated H2SO4 the initiation step is

  1. protonation of alcohol molecule
  2. formation of an ester
  3. formation of carbocation
  4. elimination of water