Which of the following statement is wrong regarding lanthanoids?

• Ln(III) compounds are predominantly ionic in character.

• Ln(III) compound are generally colourless

• Ln(III) hydroxide are mainly basic in nature

• The ionic size of Ln(III) ions decreses with increasing atomic number.

The vant Hoffs factor 'i' accounts for

• extend of solubility

• extent of mobility of solute

• extent of dissolution of solute

• extent of dissociation of solute

Which one of the following noble gas has an unusual property of diffusing through the materials such as rubber, glass or plastic?

• Kr

• Ne

• Ar

• He

When the pure solvent diffuses out of the solution through the semi-permeable membrane then the process is called

• sorption

• dialysis

• reverse osmosis

• osmosis

Hydrogenation of vegetable oils in presence of finely divided nickel as catalyst.The reaction is

• enzyme catalysed reaction

• homogeneous catalysis

• heterogeneous catalysis

• liquid catalysed reaction

Which of the following aqueous solution has highest freezing point?

• 0.1 molal Al₂(SO₄)₃

• 0.1 molal BaCl₂

• 0.1 molal AlCl₃

• 0.1 molal NH₄Cl

In the electrolysis of aqueous sodium chloride solution, which of the half cell reaction will occur at anode?

• 2H₂O (l) → O₂ + 4H⁺ +4e^-, E${}_{\mathrm{cell}}^{°}= +1.23\mathrm{V}$

• 2H⁺(aq) + e^- → 1/2H_{2,${\mathrm{E}}_{\mathrm{cell}}^{°}= -0.00\mathrm{V}$}

• Na⁺ (aq) + e^- → Na(s) E${}_{\mathrm{cell}}^{°}= -2.71\mathrm{V}$

• Cl^-(aq) → 1/2 Cl₂ + e^-, E${}_{\mathrm{cell}}^{°}=1.36\mathrm{V}$

38.

The metal extracted by leaching with a cyanide is

• Al

• Na

• Cu 

• Ag

Select wrong chemical reaction among the following.

• 8NH₃ + 3Cl₂ → 6NH₄Cl + N₂

• 2Ca(OH)₂ + Cl₂ → Ca(OCl)₂ + CaCl₂ + 2H₂O

• 2NaOH + Cl₂ → 2NaCl + H₂ + O₂

• MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O

The standard reduction potential at 298K the following half cell reaction.

Zn²⁺(aq) + 2e^- → Zn(s); E°= -0.762V

Cr³⁺(aq) + 3e^- → Cr(s); E°= -0.740V

2H⁺(aq) + 2e^- → H₂(g); E°= 0.0V

F₂(g) + 2e^- → 2F^-(aq); E°= 2.87V

Which of the following is strongest reducing agent?

• Zn(s)

• Cr(s)

• H₂(g)

• F₂(g)