'925 fine silver' means an alloy of

• 7.5% Ag and 92.5% Cu

• 92.5% Ag and 7.5% Cu

• 80% Ag and 20% Cu

• 90% Ag and 10% Cu

Sterling silver is

• AgNO₃

• Ag₂S

• Alloy of 80% Ag+ 20% Cu

• AgCl

Across the lanthanide series, the basicity of the lanthanide hydroxides

• increases

• decreases

• first increases and then decreases

• first decreases and then increases

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

• 36

• 24

• 33

• 30

Transition metals usually exhibit highest oxidation states in their

• chlorides

• fluorides

• bromides

• iodides

Identify the statement which is not correct regarding CuSO₄

• It react with KI to give iodine

• It react with KCl to give Cu₂Cl₂

• It react with NaOH and glucose to give Cu₂O.

• It gives CuO on strongly heating in air.

Which one of the following sets correctly represents the increase in the paramagnetic property of the ions?

• Cu²⁺ > V ²⁺ > Cr²⁺ > Mn²⁺

• Cu²⁺ < Cr²⁺  < V ²⁺ < Mn²⁺

• Cu²⁺ < V ²⁺ < Cr²⁺ < Mn²⁺

• V ²⁺ < Cu²⁺  < Cr²⁺ < Mn²⁺

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 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

Which of the following is not a characteristic of transition elements?

• Variable oxidation states

• Formation of coloured compounds

• Formation of interstitial compounds

• Natural radioactivity