An electronic transition in hydrogen atom results in the formation of H_α line of hydrogen in Lyman series, the energies associated with the electron in each of the orbits involved in the transition (in kcal mol^-1) are 

• -313,6, - 34.84

• -313.6, - 78.4

• -78.4,- 34.84

• -78.4,-19.6

The velocities of two particles A and B are 0.05 and 0.02 ms^-1 respectively. The mass of B is five times the mass of A. The ratio of their de-Broglie's wavelength is

• 2 : 1

• 1 : 4

• 1 : 1

• 4 : 1

The atomic numbers of elements A, B, C and D are Z - 1; Z; Z + 1 and Z + 2, respectively. If 'B' is a noble gas, choose the correct answers from the following statements-

1) 'A' has higher electron affinity.

(2) 'C' exists in +2 oxidation state. 

(3) 'D' is an alkaline earth metal.

• (1) and (2)

• (2) and (3)

• (1) and (3)

• (1), (2) and (3)

The bond length of HCl molecule is 1.275 Å and its dipole moment is 1.03 D. The ionic character of the molecule (in percent) (charge of the electron = 4.8 × 10^-10 esu) is

• 100

• 67.3

• 33.66

• 16.83

Which one of the following is a correct set ?

• H₂O, sp³, angular

• BCl₃, sp³, angular

• NH${}_4^{+}$, dsp², square planar

• CH₄, dsp², tetrahedral

Match the following:

The correct match is

• A - iv; B - i; C - ii; D - iii

• A - v; B - i; C - ii; D - iii

• A - iv; B - i; C - iii; D - ii

• A - i; B - iv; C - ii; D - iii

When 25 g of a non-volatile solute is dissolved in 100 g of water, the vapour pressure is lowered by 2.25 × 10^-1 mm. If the vapour pressure of water at 20°C is 17.5 mm, what is the molecular weight of the solute ?

• 206

• 302

• 350

• 276

50 mL of H₂O is added to 50 mL of 1 × 10^-3 M barium hydroxide solution. What is the pH of the resulting solution ?

• 3.0

• 3.3

• 11.0

• 11.7

For a crystal, the angle of diffraction (2 θ) is 90° and the second order line has a d value of 2.28 Å. The wavelength (in Å) of X-rays used for Bragg's diffraction is

• 1.612

• 2.00

• 2.28

• 4.00

In a 500 mL flask, the degree of dissociation of PCl₅ at equilibrium is 40% and the initial amount is 5 moles. The value of equilibrium constant in mol L^-1 for the decomposition of PCl₅ is

• 2.33

• 2.66

• 5.32

• 4.66