1 mol each of the following compounds is dissolved in 1L of solution. Which will have the largest $∆{\mathrm{T}}_{\mathrm{b}}$ value?

• HF

• HCl

• HBr

• HI

Carbon and CO gas are used to reduce which of the following pairs of metal oxides for extraction of metals?

• FeO, SnO

• SnO, ZnO

• BaO, Na₂O₂

• FeO, ZnO

Which of the following metal ions will form complexes with the same magnetic moment and geometry irrespective of the nature of ligands?

• Ni²⁺

• Fe²⁺

• Cu²⁺

• Co²⁺

34.

XeF₆ on complete hydrolysis produces

• XeOF₄

• XeO₂F₂

• XeO₃

• XeO₂

Decay constant of a radioactive substance is 69.3 sec^-1, find ${\mathrm{t}}_{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$16$}\right.}$ of the same substance.

• 4 × 10^-2 sec

• 2 × 10^-2 sec

• 1 × 10^-2 sec

• None of these

The element which is the most abundant in the earth crust is

• O

• S

• Al

• H

Wavelength of red light is absorbed by the complex

• [Cu(CN)₄]^2-

• [Cu(NH₃)₄]²⁺

• CuSO₄

• Cu(CN)₂

In the change[Cu(H₂O)₆F]²⁺ $\stackrel{\mathrm{HCl}}{\to }$ [CuCl(H₂O)₅]⁺, the colour changes from

• blue to green

• blue to pink

• pink to green

• pink to blue

Which of the following does not contain any coordinate bond?

• H₃O⁺

• BF${}_4^{-}$

• HF${}_2^{-}$

• NH${}_4^{+}$

Assertion : Copper sulphate solution is not stored in zinc vessel.

Reason : Zinc forms complex with CuSO₄.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.