The wave number of the spectral line in the emission spectrum of hydrogen will be equal to $\frac{8}{9}$ times the rydberg's constant if the electron jumps from

• n =3 to n =1

• n = 10 to n=1

• n=9 to n=1

• n = 2 to n=1

Consider the following gaseous equilibria with equilibrium constants K₁ and K₂ respectively.

$$\begin{gathered} {\mathrm{SO}}_2\left(\mathrm{g}\right) + \frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \rightleftharpoons {\mathrm{SO}}_3\left(\mathrm{g}\right) \\ 2{\mathrm{SO}}_3\left(\mathrm{g}\right) \rightleftharpoons 2{\mathrm{SO}}_2 \left(\mathrm{g}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \\ \mathrm{The} \mathrm{equilibrium} \mathrm{constants} \mathrm{are} \mathrm{related} \mathrm{as} \end{gathered}$$

• ${\mathrm{K}}_1^2 = \frac{1}{{\mathrm{K}}_2}$

• $2{\mathrm{K}}_1= {\mathrm{K}}_2^2$

• ${\mathrm{K}}_2=\frac{2}{{\mathrm{K}}_1^2}$

• ${\mathrm{K}}_2^2=\frac{1}{{\mathrm{K}}_1}$

Enthalpy of vaporization of benzene is + 35.3 kJ mol^-1at its boiling point, 80C. The entropy change in the transition of the vapour to liquid at its boiling point in [JK^-1mol^-1] is

• -441

• -100

• +441

• +100

Which one of the following conversions involve change in both hybridisation and shape?

• CH₄ → C₂H₆

• NH₃ → NH${}_4^{+}$

• BF₃ → BF${}_4^{-}$

• H₂O → H₃O⁺

In the reversible reaction,

A(s) + B(g) $\rightleftharpoons$C (g) + D(g) ΔG^° = -350kJ

Which one of the following statements is true?

• The entropy change is negative

• Equilibrium constant is greater than one

• The reaction should be instantaneous

• The reaction is thermodynamically not feasible

The amount of heat evolved when 500 cm³ of 0.1 M HCl is mixed with 200 cm³ of 0.2 M NaOH is

• 2.292 kJ

• 1.292 kJ

• 0.292 kJ

• 3.392 kJ

During the adsorption of krypton on activated charcoal at low temperature.

• ΔH > 0 and ΔS < 0

• ΔH < 0 and ΔS < 0

• ΔH > 0 and ΔS > 0

• ΔH < 0 and ΔS < 0

The set of quantum numbers for the outermost electron for copper in its ground state is

• 4, 1, 1 +1/2

• 3, 2, 2, +1/2

• 4, 0, 0, +1/2

• 4, 2, 2, +1/2

Peroxide ion ......
(i) has five completely filled antibonding molecular orbitals
(ii) is diamagnetic
(iii) has bond order one
(iv) is isoelectronic with neon
Which one of these is correct?

• (ii) and (iii)

• (i), (ii) and (iv)

• (i), (ii) and (iii)

• (i) and (iv)

A mixture of CaCl₂ and NaCl weighing 4.44 g is treated with sodium carbonate solution to precipitate all the Ca²⁺ ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get 0.56 g of Cao. The percentage of NaCl in the mixture (atomic mass of Ca = 40) is

• 75

• 30.6

• 25

• 69.4