Which of the following sets of qunatum numbers correct?

• n =5, l=4, m=0, s=+1/2

• n= 3, l=3, m=+3, s= +1/2

• n=6, l=0, m=+1, s= =1/2

• n=4, l= 2, m=+2, s=0

Which of the following behaves as Lewis acid and not as Bronsted acid ?

• HCl

• H₂SO₄

• HSO${}_3^{-}$

• SO₃

The pair of elements having approximately equal ionisation potential is

• Al, Ga

• Al, Si

• Al, Mg

• Al, B

Water is well known amphoprotic solvent. In which chemical reaction water is behaving as a base?

• H₂SO₄ + H₂O → H₃O⁺ + HSO${}_4^{-}$

• H₂O + H₂O → H₃O⁺ + OH^-

• H₂O + NH${}_2^{-}$ → NH₃ + OH^-

• H₂O + NH₃ → NH${}_4^{+}$ + OH^-

Which of the following is not a equilibrium ?

• Ice $\rightleftharpoons$ Water

• I₂(s) $\rightleftharpoons$ I₂(g)

• S (l) $\rightleftharpoons$ S (g)

• 3O₂ $\rightleftharpoons$2O₃

2.5 L of NaCl solution contain 5 moles of the solute. What is the molarity ?

• 5 M

• 2 M

• 2.5 M

• 12.5 M

The calculated bond order in O${}_2^{-}$ ions is

• 1

• 1.5

• 2

• 2.5

The entropy of a perfectly crystalline material is zero at 0°C. This is statement of

• first law of thermodynamics

• second law of thermodynamics

• third law of thermodynamics

• law of conservation of energy

9.

In acidic medium, the equivalent weight of  K₂Cr₂O₇ ( Mol. wt. = M) is

• M

• M/2

• M/3

• M/6

When a metal atom combines with a non-metal atom, the non-metal atom will

• lose electrons and decrease in size

• lose electrons and increase in size

• gain electrons and decrease in size

• gain electrons and increase in size