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d- and f-Block Elements

JEE Main 2025 (Online) 4th April Morning ShiftNumericalMedium📈 Topic in 16% papers+4
Ques. 1JEE Main 2025, 4 April (Morning Shift)

KMnO4 acts as an oxidising agent in acidic medium. 'X' is the difference between the oxidation states of Mn in reactant and product. 'Y' is the number of 'd' electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The value of X + Y is .

Answer

10

Solution

In acidic medium:

MnO4- + 8H+ + 5e- Mn2+ + 4H2O

Oxidation state of Mn changes from +7 to +2 ⇒ X = 7 − 2 = 5

Acetate ion test: neutral FeCl3 gives a deep red colour with acetate; on boiling, a brown-red precipitate of basic iron(III) acetate, Fe(OH)2(CH3COO), is formed.

Fe is in +3 state: Fe3+ = [Ar] 3d5 ⇒ Y = 5

∴ X + Y = 5 + 5 = 10

Answer: 10

Keep practising — d- and f-Block Elements

Ques. 2JEE Main 2025, 4 April (Evening Shift)

The incorrect relationship in the following pairs in relation to ionisation enthalpies is :

  1. Mn2+ < Fe2+
  2. Mn+ < Mn2+
  3. Mn+ < Cr+
  4. Fe2+ < Fe3+
Ques. 3JEE Main 2025, 3 April (Morning Shift)

The metal ions that have the calculated spin-only magnetic moment value of 4.9 B.M. are : Choose the correct answer from the options given below:

  1. A, D and E Only
  2. A, B and E Only
  3. A, C and E Only
  4. B and E Only
Ques. 4JEE Main 2025, 3 April (Morning Shift)

Consider the following reactions A + Little amountNaCl + H2SO4 CrO2Cl2 + Side Products CrO2Cl2(Vapour) + NaOH B + NaCl + H2O B + H+ C + H2O The number of terminal 'O' present in the compound 'C' is

Ques. 5JEE Main 2025, 3 April (Evening Shift)

Given below are two statements: In the light of the above statements, choose the correct answer from the options given below

  1. Statement I is true but Statement II is false
  2. Both Statement I and Statement II are true
  3. Both Statement I and Statement II are false
  4. Statement I is false but Statement II is true
Ques. 6JEE Main 2025, 3 April (Evening Shift)

Among Sc, Mn, Co and Cu, identify the element with highest enthalpy of atomisation. The spin only magnetic moment value of that element in its +2 oxidation state is BM (in nearest integer).

Ques. 7JEE Main 2025, 2 April (Evening Shift)

The spin-only magnetic moment value of Mn+ ion formed among Ni, Zn, Mn and Cu that has the least enthalpy of atomisation is . (in nearest integer) Here n is equal to the number of diamagnetic complexes among K2[NiCl4], [Zn(H2O)6]Cl2, K3[Mn(CN)6] and [Cu(PPh3)3I]

Ques. 8JEE Main 2025, 29 January (Morning Shift)

The correct option with order of melting points of the pairs (Mn, Fe), (Tc, Ru) and (Re, Os) is :

  1. Fe < Mn, Ru < Tc and Re < Os
  2. Fe < Mn, Ru < Tc and Os < Re
  3. Mn < Fe, Tc < Ru and Re < Os
  4. Mn < Fe, Tc < Ru and Os < Re
Ques. 9JEE Main 2025, 29 January (Morning Shift)

The molar mass of the water insoluble product formed from the fusion of chromite ore (FeCr2O4) with Na2CO3 in presence of O2 is g mol-1.

Ques. 10JEE Main 2025, 28 January (Morning Shift)

Consider 'n' is the number of lone pair of electrons present in the equatorial position of the most stable structure of ClF3. The ions from the following with 'n' number of unpaired electrons are Choose the correct answer from the options given below:

  1. B and D Only
  2. A, D and E Only
  3. B and C Only
  4. A and C Only
Ques. 11JEE Main 2025, 28 January (Morning Shift)

Which of the following oxidation reactions are carried out by both K2Cr2O7 and KMnO4 in acidic medium? Choose the correct answer from the options given below :

  1. A, B and C Only
  2. C, D and E Only
  3. B, C and D Only
  4. A, D and E Only

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