PYQSide ExamsMy practice

d- and f-Block Elements · Question 29

NEET 2016 (Phase 1)MCQEasy📈 Topic in 0% papers+4−1
1

Which one of the following statements is correct when SO2 is passed through acidified K2Cr2O7 solution?

  1. SO2 is reduced.
  2. Green Cr2(SO4)3 is formed.
  3. The solution turns blue.
  4. The solution is decolourised.

Answer

(2) Green Cr2(SO4)3 is formed.

Solution

Acidified dichromate is a strong oxidising agent; SO2 acts as a reducing agent and is oxidised to sulphate:

K2Cr2O7 + H2SO4 + 3SO2 K2SO4 + Cr2(SO4)3 + H2O

Cr is reduced from +6 to +3 ⇒ the orange solution turns green due to Cr2(SO4)3.

∴ SO2 is oxidised (not reduced), and the solution turns green (not blue or colourless).

Answer: (2)

NEET 2016 (Phase 1)

Keep practising — d- and f-Block Elements

2

The electronic configuration of Eu (Atomic No. 63), Gd (Atomic No. 64) and Tb (Atomic No. 65) are

  1. [Xe]4f6 5d1 6s2, [Xe]4f7 5d1 6s2 and [Xe]4f8 5d1 6s2
  2. [Xe]4f7 6s2, [Xe]4f7 5d1 6s2 and [Xe]4f9 6s2
  3. [Xe]4f7 6s2, [Xe]4f8 6s2 and [Xe]4f8 5d1 6s2
  4. [Xe]4f6 5d1 6s2, [Xe]4f7 5d1 6s2 and [Xe]4f9 6s2
NEET 2016 (Phase 1)
3

Which one of the following statements related to lanthanoids is incorrect?

  1. Europium shows +2 oxidation state.
  2. The basicity decreases as the ionic radius decreases from Pr to Lu.
  3. All the lanthanons are much more reactive than aluminium.
  4. Ce(+4) solutions are widely used as oxidizing agent in volumetric analysis.
NEET 2016 (Phase 2)
4

Gadolinium belongs to 4f series. Its atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?

  1. [Xe]4f9 5s1
  2. [Xe]4f7 5d1 6s2
  3. [Xe]4f6 5d2 6s2
  4. [Xe]4f8 6d2
AIPMT 2015
5

Magnetic moment 2.84 B.M. is given by (At. nos. Ni = 28, Ti = 22, Cr = 24, Co = 27)

  1. Cr2+
  2. Co2+
  3. Ni2+
  4. Ti3+
AIPMT 2015 (Cancelled)
6

Because of lanthanoid contraction, which of the following pairs of elements have nearly same atomic radii? (Numbers in the parenthesis are atomic numbers)

  1. Zr(40) and Hf(72)
  2. Zr(40) and Ta(73)
  3. Ti(22) and Zr(40)
  4. Zr(40) and Nb(41)
AIPMT 2015 (Cancelled)
7

The reaction of aqueous KMnO4 with H2O2 in acidic conditions gives

  1. Mn4+ and O2
  2. Mn2+ and O2
  3. Mn2+ and O3
  4. Mn4+ and MnO2
AIPMT 2014
8

Magnetic moment 2.83 BM is given by which of the following ions? (At. nos. Ti = 22, Cr = 24, Mn = 25, Ni = 28)

  1. Ti3+
  2. Ni2+
  3. Cr3+
  4. Mn2+
AIPMT 2014
9

Reason of lanthanoid contraction is

  1. negligible screening effect of 'f'-orbitals
  2. increasing nuclear charge
  3. decreasing nuclear charge
  4. decreasing screening effect.
AIPMT 2014
10

KMnO4 can be prepared from K2MnO4 as per the reaction, 3MnO42- + 2H2O 2MnO4- + MnO2 + 4OH- The reaction can go to completion by removing OH- ions by adding

  1. CO2
  2. SO2
  3. HCl
  4. KOH
NEET 2013
11

Which of the following does not give oxygen on heating?

  1. K2Cr2O7
  2. (NH4)2Cr2O7
  3. KClO3
  4. Zn(ClO3)2
NEET 2013

All d- and f-Block Elements PYQs →

PDFDownload d- and f-Block Elements PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters