A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is :

• Z > 1 and repulsive forces are dominant

• Z < 1 and attractive forces are dominant

• Z < 1 and repulsive forces are dominant

• Z > 1 and attractive forces are dominant

4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is:

• 6p > 5f > 5p > 4d

• 6p > 5f > 4d > 5p

• 5f > 6p > 4d > 5p

• 5f > 6p > 5p > 4d

Which will make basic buffer?

• 100mL of 0.1 M CH₃COOH + 100mL of 0.1M NaOh

• 100 mL of 0.1 M HCl + 200 mL of 0.1 M NH₄OH

• 100 mL of 0.1 M HCl + 100 mL of 0.1 M NaOH

• 50 mL of 0.1 M NaOH + 25 mL of 0.1 M CH₃COOH

Which of the following diatomic molecular species has only π bonds according to Molecular Orbital Theory?

• N₂

• C₂

• Be₂

• O₂

Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is:(Given that 1 L bar = 100 J)

• 5 kJ

• 25 J

• 30 J

• -30 J

Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region?

• Balmer series

• Paschen series

• Brackett series

• Lyman series

Conjugate base for BrÖnsted acids H₂O and HF are :

• H₃O⁺ and F^-, respectively

• OH^- and F^-, respectively

• H₃O⁺ and  H₂F⁺, respectively

• OH^- and H₂F⁺, respectively

In which case change in entropy is negative?

• Expansion of a gas at constant temperature

• Sublimation of solid to gas

• 2H(g) → H₂(g)

• Evaporation of water

9.

The manganate and permanganate ions are tetrahedral, due to :

• There is no π-bonding

• The π- bonding involves overlap of p-orbitals of oxygen with p-orbitals of manganese.

• The π-bonding involves overlap of d-orbitals of oxygen with d-orbitals of manganese

• The π-bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese

pH of a saturated solution of Ca(OH)₂ is 9. The solubility product(K_sp) of Ca(OH)₂ is:

• 0.25 × 10^-10

• 0.5 × 10^-15

• 0.125 × 10^-15

• 0.5 × 10^-10