The element with the electronic configuration 1s² 2s²2p⁶3s²3p⁶3d¹⁰4s¹ is

• Cu

• Ca

• Cr

• Co

Among the following, the isoelectronic specie (s) is/are

(i)  O^2-, F^-, Na⁺, Mg²⁺

(ii) Na⁺, Mg⁺, Al³⁺, F^-

(iii) N^3-,  O^2-, F^-, Ne

• (i) and (ii)

• (i), (ii) and (iii)

• (ii) and (iii)

• (i) and (iii)

3.

What is the atomic number of the element with symbol Uus?

• 117

• 116

• 115

• 114

Match the following

List I	List II
(a) PCl3	(i) Square planar
(b) BF3	(ii) T-shape
(c) ClF3	(iii) Trigonal pyramidal
(d) XeF4	(iv) See- saw
	(v) Trigaonal planar

• (a)    (b)  (c)  (d)
  (iv)   (ii)   (i)    (iii)

• (a)    (b)   (c)    (d)
  (iii)   (v)   (ii)    (iv)

• (a)  (b)    (c)   (d)
  (iii)   (v)   (ii)   (i)

• (a)   (b)   (c)    (d)
  (iii)   (v)   (ii)   (v)

If the kinetic energy in J, of CH₄ (molar mass =16 g mol^-1) at T(K) is X, the kinetic energy in J, of O₂, (molar mass = 32 g mol^-1) at the same temperature is

• X

• 2X

• X²

• X/2

The given figure shows the Maxwell distribution of molecular speeds of a gas at three different temperatures T_1,T_2, and T₃. The correct order of temperature is

• T₁ > T₂ > T₃

• T₁ > T₃ > T₂

• T₃ > T₂ > T₁

• T₂ > T₃ > T₁

The hybridisation of each carbon in the following compound respectively is CH₃-CO-CH₂CN

• sp³,sp²,sp³,sp

• sp³,sp³,sp²,sp

• sp³,sp²,sp, sp³

• sp²,sp, sp³, sp³

Given that N₂(g) + 3H₂(g) → 2NH₃(g): Δ_rH° =-92kJ, the standard molar enthalpy of formation in kJ mol^-1 of NH₃(g) is 

• -92

• +46

• +92

• -46

Which one of the following is correct?

• The equilibrium constant (K_c) is independent of temperature

• The value of K_c is independent of initial concentrations of reactants and products

• At equilibrium, the rate of the forward reaction is twice the rate of the backward reaction.

• The equilibrium constant (K_c) for the reaction

  $\mathrm{Ni}\left(\mathrm{s}\right) + 4\mathrm{CO}\left(\mathrm{g}\right) \rightleftharpoons \mathrm{Ni}\left(\mathrm{CO}{)}_4\right(\mathrm{g}) \mathrm{is}, \frac{\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]}{\left[\mathrm{CO}\right]}$

pH of an aqueous solution of NH₄Cl is

• 7

• >7

• <7

• 1