Consider the formal charges on N and B in H₃N-BF₃ and indicate which of the following is true?

• N is +ve and B is -ve

• N is --ve and B is +ve

• both N and B carry similar +ve or -ve charges

• charge discrimination is difficult to make

Consider (i) CO₂ (ii) CCl₄ (iii) C₆Cl₆ and (iv) CO and tell which of the following statements is correct?

• (i), (ii) and (iii) only have zero dipole moment

• (i), (ii) and (iv) only have zero dipole moment

• only (iv) has zero dipole moment

• All have zero dipole moment

There is a general understanding of ionic radius based on the nuclear charges and the number of electrons surrounding the nucleus which generally works very well. Which one of the following represents the correct decreasing order ofionic radius for C^4-, N^3-, O^2- and F^-?

• C^4- > N^3- > O^2- > F^- 

• F^-> O^2- > N^3- > C^4-

• O^2- > N^3- > C^4- > F^-

• F^- > N^3- > C^4- > O^2-

'No two electrons in an atom can have the same set of  quantum numbers.' This principle is known by which one of the following?

• Zeeman's exclusion principle

• Stark's exclusion principle

• Pauli's exclusion principle

• Hersbach's exclusion principle

The unit of equilibrium constant for the following reaction is

 $2{\mathrm{NO}}_2\left(\mathrm{g}\right) \rightleftharpoons {\mathrm{N}}_2{\mathrm{O}}_4 \left(\mathrm{g}\right)$

• mol L^-1

• L mol^-1

• mol^-1 L^-1

• equilibrium constant is unitless

Which one of the following represents the correct state of hybridisation of P in PCl₅ ?

• s⁰p³

• sp³d

• s²p³

• sp²d²

Where of the ${\mathrm{O}}_2^{-}, {\mathrm{O}}_2^{2-},$ BN and NN is/are paramagnetic ?

• NN

• ${\mathrm{O}}_2^{2-}$

• BN

• ${\mathrm{O}}_2^{-}$

What is the wavelength associated with a tennis ball of mass 10³ g and travelling at a velocity of 6.626 ms^-1 ?[h = 6.626 x 10^-34 Js^-1].

• 10^-34 m

• 10^-31 m

• 6.626 m

• 6.626 × 10^-31 m

What is the energy required to move the electron from ground state of H atom to the first excited state? Given that the ground state energy of H atom is 13.6 eV and that the energy E_n of an electron in nth orbital of an atom or ion of atomic number Z is given by the equation En= - (13.6Z² /n²).

• 13.6 eV

• 3.4 eV

• 10.2 eV

• -10.2 eV

Which electron orbitals are designated by
(i) n = 2, l = 1, m = 0;
(ii) n = 3, l=2, m = O;
(iii) n=4, l = 2, m=1 and
(iv) n = 5, l=3, m=3 respectively?

• 2p, 3d, 4d and 5f, respectively

• 2p, 3d, 4d and 5d, respectively

• 2p, 3d, 4f and 5f, respectively

• 2p, 3p, 4d and 5f, respectively