1.

pH of a saturated solution of Ba(OH)₂ is 12. The value of solubility product K_sp of Ba(OH)₂ is

• 3.3 x 10^-7

• 5.0 x 10^-7

• 4.0 x 10^-6

• 4.0 x 10^-6

Maximum number of electrons in a subshell with l =3 and n=4 is

• 14

• 16

• 10

• 10

In which of the following reactions, standard reaction entropy changes (ΔS^o) is positive and standard Gibb's energy change (ΔG^o) decreases sharply with increasing temperature?

• C (graphite) +1/2 O₂ (g) → CO (g)

• CO (g) +1/2 (g) → CO₂ (g)

• Mg(s)  +1/2O₂ (g) → MgO (s)

• Mg(s)  +1/2O₂ (g) → MgO (s)

Equimolar solutions of the following substances were prepared separately, which one of these will record the highest pH value?

• BaCl₂

• AlCl₃

• LiCl

• LiCl

50 mL of each gas A and of gas B takes 150 and 200 s respectively for effusing through a pin hole under the similar conditions. If molecular mass of gas B is 36, the molecular mass of gas A will be

• 96

• 128

• 20.2

• 20.2

The correct set four quantum number for the valence electron of rubidium atom (z=37) is 

• 5,1,1, +1/2

• 6,0,0,+1/2

• 5,0,0 +1/2

• 5,0,0 +1/2

Buffer solutions have constant acidity and alkalinity because

• these give unionised acid or base on reaction with added acid or alkali

• acids and alkalies in these solutions are shielded from attack by other ions.

• they have a large excess of H⁺ or OH^- ions

• they have a large excess of H⁺ or OH^- ions

The enthalpy of fusion of water is 1.435 Kcal/mol. The molar entropy change for the melting of ice of at 0^o C is

• 10.52 cal/(mol K)

• 21.04 cal/(mol K)

• 5.260 cal/ (mol K)

• 5.260 cal/ (mol K)

Bond order of 1.5 is shown by

• O₂⁺

• O₂^-

• O₂^2-

• O₂^2-

Standard enthalpy of vaporisation Δ_vapH^θ for water for water at 100^oC is 40.66 kJ mol^-1. The internal energy of vaporisation of water at 100^o C (in KJ mol^-1) is

(Assume water vapour to behave like an ideal gas.)

• +37.56

• -43.76

• +43.76

• +43.76