The d-And-f-Block Elements

Which of the following does not exist?

• KI + I₂ → KI₃

• KF + F₂ → KF₃

• KBr + ICI₂ → K[BrICl]

• KF + BrF₃ → K[BrF₄]

Which of the following does not represent the correct order of the property indicated?

• Sc³⁺ > Cr³⁺ > Fe³⁺ >Mn³⁺ - ionic radii

• Sc < Ti < Cr < Mn - density

• Mn²⁺ >Ni²⁺ > Co²⁺ <Fe²⁺ - ionic radii

• FeO < CaO < MnO < CuO - basic nature

Which of the following oxidation states is the most common among the lanthanoids?

• 4

• 2

• 3

• 5

Mn₂O₇ dissolves in water to give an acid. The colour of the acid is

• green

• blue

• purple

• red

• 7.5% Ag and 92.5% Cu

• 92.5% Ag and 7.5% Cu

• 80% Ag and 20% Cu

• 90% Ag and 10% Cu

Assertion (A): Cu²⁺ and Cd²⁺ are separated by first adding KCN solution and then passing H-S gas.
Reason (R): KCN reduces Cu²⁺ to Cu⁺ and forms a complex with it.
The correct answer is

• Both (A) and (R) are true and (R) is the correct explanation of (A)

• Both (A) and (R) are true but (R) is not the correct explanation of (A)

• (A) is true but (R) is not true

• (A) is not true but (R) is true

The effective atomic number of cobalt in the complex [Co(NH₃)₆]⁺ is

• 36

• 24

• 33

• 30

The correct formula of the complex tetraammineaquachlorocobalt (III) chloride is

• [Cl(H₂O)(NH₃)₄Co]Cl

• [CoCl(H₂O)(NH₃)₄]Cl

• [Co(NH₃)₄(H₂O)Cl]Cl

• [CoCl(H₂O)(NH₃)₄]Cl₂

Across the lanthanide series, the basicity of the lanthanide hydroxides

• increases

• decreases

• first increases and then decreases

• first decreases and then increases

Sterling silver is

• AgNO₃

• Ag₂S

• Alloy of 80% Ag+ 20% Cu

• AgCl