Trying to find the right answer to this..

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

The d-And-f-Block Elements

Short Answer Type

181.

Explain the following facts:
Transition metals form coloured complexes.

175 Views

182.

Give reasons:
Among transition metals, the highest oxidation state is exhibited in oxoanions of a metal.

434 Views

183.

Give reasons:
Ce⁴⁺ is used as an oxidising agent in volumetric analysis.

422 Views

184.

Give reasons:
Zn²⁺ salts are white while Cu²⁺ salts are blue.

186 Views

185.

Why La, Gd and Lu has low value of 3rd ionisation enthalpies?

301 Views

186. Why is cerium a good analytical reagent?

317 Views

187. Given below are the electrode potential values, E° for some of the first row of transition elements:
Elements V(23) Cr(24) Mn(25)Fe(26)Co(27)Ni(28) Cu(29)
E°_M²⁺/M(V) –1.18 – 0.91 – 0.44 – 0.28 –0.28 –0.25 +0.34
Explain the irregularities in these values on the basis of electronic structures of atoms.

279 Views

188.

Complete the following reaction equations:
(i) Cr₂O₇ ² + Sn²⁺ + H⁺ →
(ii) MnO₄^–+ Fe²⁺ + H⁺ →

625 Views

189.

Actinide cations are coloured? Why?

511 Views

190. Eu²⁺, Yb²⁺ are good reductants whereas Tb⁺⁴ is an oxidant. Why?

The electronic configuration of Eurponium is 4f⁷ 6s² and Ytterbium is 4f¹⁴ 6s². Eu and Yb in +2 oxidation states acquires half filled (4f⁷) and fully filled (4f ¹⁴) configuration but still they oxidises to their common +3 state and thus acts as strong reducing agents or reductants.
Tb in +4 state has 4f⁷ half filled stable configuration but it readily gets reduced to common +3 state and hence acts as oxidant.

478 Views