In the following, the element withthe highest electropositivity is

• copper

• silver

• gold

• caesium

Mark the wrong statement. When Na₂S is added to sodium nitroprusside solution,

• beautiful violet colour is produced

• a complex [Fe(CN)₅NOS]^4- is formed

• a complex [Fe(CN)₅NOS]^2- is formed

• a complex [Fe(CN)₅NOS] is formed

Iron loses magnetic property at

• melting point

• 1000 K

• Curie point

• boiling point

Stainless steel does not rust because

• chromium and nickel combine with iron

• chromium forms an oxide layer and protects iron from rusting

• nickel present in it, does not rust

• iron forms a hard chemical compound with chromium present in it

The atomic number of Ni and Cu are 28 and 29 respectively. The electronic configuration. 1s²2s²2p⁶3s²3p⁶3d¹⁰ represents.

• Cu⁺

• Cu²⁺

• Ni²⁺

• Ni

516.

Which of the following types of metals form the most efficient catalysts ?

• Alkali metals

• Alkaline earth metals

• Transition metals

• All of the above

A transition metal ion exists in its highest oxidation state. It is expected to behave as :

• a chelating agent

• a central metal in a coordination compound

• an oxidising agent

• a reducing agent

The highest magneticmoment is shown by the transition metal ion with the configuration :

• 3d²

• 3d⁵

• 3d⁷

• 3d⁹

In the periodic table metals usually used as catalysts belong to

• f-block

• d-block

• p-block

• s-block

Which of the following forms a colourless solution in aqueous medium?

• Cr³⁺

• C³⁺

• Sc³⁺

• Ti³⁺