32 Year NEET Previous Year Questions: The d & f-Block Elements - 1 - NEET MCQ

In moist air, corrosion of iron takes place in the form of rust (Fe₂O₃ + Fe(OH)₃) . As iron is most reactive among all.

Argentite or silver glance (Ag₂S) is an ore of Ag.

Potassium ferrocyanide solution is added to Fe³⁺ ions in solution to give deep blue solution or precipitate.

AgBr is highly photosensitive and is used in photographic films and plates.

When steel is heated in presence of NH₃ , iron nitride on the surface of steel is formed which imparts a hard coating. This process is called nitriding.

Cyanide process is used in the metallurgy of Ag

[ Ne]3s²3p ⁵ is the electronic configuration of a p-block element whereas other configuration are those of d-block elements

PbI₂ is yellow and is called golden spangles.

Electronic configuration of Cu(29) is 1s² 2s² 2p⁶ 3p² 3p⁶ 4s¹ 3d¹⁰ and not 1s², 2s² 2p⁶ 3s² 3p⁶ 4s², 3d⁹ due to extra stability of fully filled orbitals.

Cinnabar (HgS) is an ore of Hg.

General electronic configuration of transition elements is (n - 1)d^{1 -10}ns^{1- 2}

At cathode :  

At anode : 

Galvanisation is the process of deposition of zinc metal on the surface of Fe to prevent it from rusting etc. Zinc forms a protective layer of basic carbonate (ZnCO₃. Zn(OH)₂) on it.

The minimum oxidation state in transition metal is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of the 4s and 3d electrons.
Ti  3d² 4s² hence minimum oxidation state is +2 and maximum oxidation state is +4. Thus the common oxidation states of Ti are +2, +3 & +4

Actinides have variable valency due to very small difference in energies of 5f, 6d and 7s orbitals. Actinides are the elements from atomic number 89 to 103.

Pm is obtained by synthetic method.

Stainless steel contains 73% Fe, 18% Cr and 8% Ni.

The smaller is the size of cation, the more is heat of  hydration. Since hydration is exothermic process, thus heat evolves and hence system having lower energy are stable.

Hence ion is obtained.

We know that regular decrease in the size of the atoms and ions is called lanthanide contraction. In vertical column of transition elements there is a very small change in size and some times size is found same from second member to third member.The similarity in size of the atoms of Zr and Hf is evident due to the object of lanthanide contraction. Therefore Zr and Hf both have same radius 160 pm.

We know that atomic number of gadolinium is 64. Therefore the electronic configuration of gadolinium is [Xe] 4f⁷ 5d¹ 6s². Because the half filled and fully filled orbitals are more stable.

Pig iron is the most impure form of iron and contains the highest proportion of carbon (2.5 – 4%).

Since graphite is a form of carbon, A is the correct answer.

We know that lanthanides Eu, La, Gd shows +2, +3, +3 and +3 oxidation states respectively only. while actinides, Am shows +2, +3, +4, +5 and +6 oxidation state. Therefore American (Am) has maximum number of oxidation state.

We know that chromium (III) salts dissolve in water to give violet solution. The violet colour is due to the hydrated chromium (III) in 

By heating chromite with Na₂ CO₃, Na₂CrO₄ is obtained

[Cu (NH₃)₄]²⁺ on addition of excess of aqneous HNO₃ gives [Cu (H₂O)₄]²⁺