JEE Questions for Chemistry The D And F Block Elements Quiz 7 - MCQExams.com

Cu is less electropositive than H and thus it cannot displace hydrogen from acids.

Sc = 3d¹4s²; Sc³⁺ = 3d¹⁰; it will be colourless in aqueous solution.

In Fe (CO)₅, Fe undergoes sp³ d hybridization giving a trigonal bipymidal shape.

(n − 1)d and ns are valence shell orbitals of transition elements.

In this smelting process, the ore copper pyrites is converted into FeO which then combines with silica to give FeSiO₃ as a slag.

FeO + SiO₂ → FeSiO₃

In the reaction, X is S and Y is O₂.

22 – Carat gold is an alloy of Au and Cu.

The developer quinol reduces exposed AgBr to black Ag.

Electronic configuration of Fe atom (Z = 26) = 3d⁶ 4² ; then electronic configuration of Fe³⁺ = 3 d⁵.

Co²⁺ and Fe²⁺  ions are coloured.

Metal becomes less malleable and ductile.

CO burns with a blue flame.

Ag₂S is dissolved in either NaCN or KCN.

Ce = [Xe]4f²5d^o6s²; oxidation states shown are + 3 and + 4.

Fe = 3d⁶ 4s²; Fe²⁺ = 3d⁶.

Due to increase in effective nuclear charge, the size of lanthanoids decreases as the atomic number increases left to right in the series.

Cu₂(SCN) is a white precipitate and is used for the gravimetric estimation of Cu(II) by first reducing it with H₂SO₃ and then precipitating Cu (I) thus obtained with SCN^-.

Variable oxidation state is one of the requirements for showing catalytic activity.

As the size of the metal atom decreases from Ti to Fe the basic character of their monoxides decreases in that order.

Eu shows +2 and + 3 oxidation states.

[Cu(NH₃)₄]SO₄ is called Schweitzer reagent.

Chinese white or zinc white or philosopher’s wool is ZnO.

Actually second ionization potential of Cu (1958 kJ/mol) is not very high as compared to first ionization potential (745 kJ/mol). In addition the gain in lattice energy due to +2 state (divalent state) in the solid. Hence the lattice energy released for cupric compounds is must higher than Cu⁺.

The transition metals and their compounds function as catalysts either because of their  ability to change oxidation state or in the case of metals , to absorb  other substances on to their  surface and activate them in the process and increase in the concentration of the reactants at the catalyst. All this is explored in the main catalysis section . But strengthening the bonds in the reacting molecules will not involved in the catalytic activity . 

The 2^nd row transition series involves filling of  4d-subshell. Hence the have general electronic configuration as [Kr] 4d^1-10, 5s^1-2