Which of the following concentration units is independent of temperature ?

• Normality

• Molarity

• Formality

• Molality

At a given temperature the equilibrium constant for the reaction of:

PCl₅ $\rightleftharpoons$ PCl₃ + Cl₂ is 2.4 × 10^-3. At the same temperature, the equilibrium constant for the reaction

PCl₃ (g) + Cl₂ (g) $\rightleftharpoons$ PCl₅ (g) is :

• 2.4 × 10^-3

• -2.4 × 10^-3

• 4.2 × 10²

• 4.8 × 10^-2

3.

For the gaseous reaction, C₂H₄ + H₂ $\rightleftharpoons$ C₂H₆; $∆$H = -130 kJ mol^-1 carried in a closed vessel, the equilibrium concentration of the C₂H₆ can definitely be increased by:

• increasing temperature and decreasing pressure

• decreasing temperature and increasing pressure

• increasing temperature and pressure both

• decreasing temperature and pressure both

The number of electrons in the valence shell of sulphur in SF₆ is :

• 12

• 10

• 8

• 11

The only non-metal which is liquid at ordinary temperature is :

• Hg

• Br₂

• NH₃

• None of these

Which of the following is correct for the reaction?

N₂(g) + 3H₂ (g) $\rightleftharpoons$ 2NH₃ (g)

• K_p = K_c

• K_p < K_c

• K_p > K_c

• Pressure is required to predict the correlation

sp³d hybridization results in :

• a square planar molecule

• an octahedron molecule

• a trigonal bipyramidal molecule

• a tetrahedron molecule

Among the following, the most acidic is :

• CH₃COOH

• ClCH₂COOH

• Cl₂CHCOOH

• Cl₂CHCH₂COOH

Rutherford's experiment on the scattering of α-particles showed for the first time that the atom has:

• electrons

• protons

• nucleus

• neutrons

For a Bohr atom angular momentum M of the electron is : (n = 0, 1, 2......)

• $\frac{{\mathrm{nh}}^2}{4\mathrm{\pi }}$

• $\frac{{\mathrm{n}}^2{\mathrm{h}}^2}{4\mathrm{\pi }}$

• $\frac{\sqrt{{\mathrm{nh}}^2}}{4\mathrm{\pi }}$

• $\frac{\mathrm{nh}}{2\mathrm{\pi }}$