The relative lowering of vapour pressure of a dilute aqueous solution containing non-volatile solute is 0.0125. The molality of the solution is about

• 0.70

• 0.50

• 0.90

• 0.80

The activation energy of exothermic reaction A → B is 80 kJ mo1^-1. The heat of reaction is 200 kJ mol^-1. The activation evergy for the reaction B → A (in kJ mol^-1) will be

• 280

• 200

• 120

• 40

The strongest base among the following is

• C₆H₅NH₂

• (C₆H₅)₂NH

• NH₃

• (C₂H₅)₂NH

The radius of the first Bohr orbit of hydrogen atom is 0.529 Å. The radius of the third orbit of H⁺ will be

• 8.46 Å

• 0.705 Å

• 1.59 Å

• 4.29 Å

Which diagram best represents the appearance of the line spectrum of atomic hydrogen in the visible region?

Which of the following is paramagnetic with bond order 0.5?

• F₂

• H${}_2^{+}$

• N₂

• O${}_2^{-}$

Match List-I with List-II and choose the correct matching codes from the choices given.

• A - 3; B - 5; C - 2; D - 1; E - 4

• A - 3; B - 5; C - 4; D - 1; E - 2

• A - 3; B - 5; C - 6; D - 1; E - 2

• A - 3; B - 5; C - 2; D - 6; E - 4

Which one of the following volume (V)- temperature (T) plots represents the behaviour of one mole of an ideal gas at one atmospheric pressure?

In which one of the following pairs the radius of the second species is greater than that of the first?

• Na, Mg

• O^2-, N^3-

• Li⁺, Be²⁺

• Ba²⁺, Sr²⁺

Match List-I with List-II Choose the correct matching codes from the choices given.

• A - 6; B - 2; C - 4; D - 5; E - 1

• A - 5; B - 4; C - 2; D - 3; E - 1

• A - 6; B - 4; C - 2; D - 3; E - 5

• A - 6; B - 4; C - 2; D - 3; E - 1