The electrons, identified by quantum numbers n and l,

(I) n = 3; l = 2; (II) n = 5; l = 0; (III) n = 4; l = 1; (IV) n = 4; l = 2; (V) n = 4; l = 0;

can be placed in order of increasing energy as-

• I < V < III < IV < II

• I < V < III < II < IV

• V < I < III < II < IV

• V < I < II < III < IV

The number of photons emitted per second by a 60 W source of monochromatic light of wavelength 663 nm is (h = 6 .63 × 10^-34 Js)

• 4 × 10^-20

• 1.5 × 10²⁰

• 3 × 10^-20

• 2 × 10²⁰

Among the following species, identify the pair having same bond order CN^-, O${}_2^{-}$, NO⁺, CN⁺

• CN^- and O${}_2^{-}$

• O${}_2^{-}$ and NO⁺

• CN^- and NO⁺

• CN^- and CN⁺

Hydration of different ions in aqueous solution is an example of

• ion-dipole interaction

• ion-induced dipole interaction

• dipole-dipole interaction

• dipole-induced dipole interaction

When a sample of gas is compressed at constant temperature from 15 atm to 60 atm, its volume changes from 76 cm³ to 20.50 m³. Which of the following  statements are possible explanations of this behaviour ?

1.The gas behaves non-ideally

2. The gas dimerises

3. The gas is adsorbed into the vessel walls

• 1, 2 and 3

• 1 and 2 only

• 2 and 3 only

• 1 only

The vapour pressure of two liquids X and Y are 80 and 60 Torr respectively. The total vapour pressure of the ideal solution obtained by mixing 3 moles of X and 2 moles of Y would be

• 68 Torr

• 140 Torr

• 48 Torr

• 72 Torr

'Hydride Gap' is referred to which region of the Periodic Table ?

• Groups 3, 4 and 5

• Groups 5, 6 and 7

• Groups 4, 5 and 6

• Groups 7, 8 and 9

8.

Which of the following pairs of substances would give same gaseous product on reaction with water?

• Na and Na₂O₂

• Ca and CaH₂

• Ca and CaO

• Ba and BaO₂

The shape of XeF₄ molecule and hybridisation of xenon in it are

• tetrahedral and sp³

• square planar and dsp²

• square planar and sp³d²

• octahedral and sp³d²

Energy released, when one atom of uranium undergoes nuclear fission according to the following reaction is (atomic mass of U = 235.060; n = 1.009; Ba= 143.881 and Kr = 89.94 7) about 

₉₂U²³⁵ + ₀n¹ → ₅₆Ba¹⁴⁴ + ₃₆Kr⁹⁰ + 2 ₀n¹

• 235 MeV

• 208 MeV

• 931.5 MeV

• 5.33 x 10²³ MeV