Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This is due to the formation of:

1.  CrO42-

2.  Cr2SO33

3.  CrSO4

4.  Cr2SO43

Subtopic:  d-Block Elements- Properties & Uses |
 60%
From NCERT
AIPMT - 2011
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Which of the following ions will exhibit colour in aqueous solutions?

1. La3+ (Z=57)

2. Ti3+ (Z=22)

3. Lu3+ (Z=71)

4. Sc3+ (Z=21)

Subtopic:  Lanthanoid & Actinoids Contraction |
 80%
From NCERT
AIPMT - 2010
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Which one of the following ions has electronic configuration [Ar] 3d6
(At. no :Mn = 25, Fe= 26, Co= 27, Ni = 28)

1. Ni3+

2. Mn3+

3. Fe3+

4. Co3+

Subtopic:  d-Block Elements- Properties & Uses |
 80%
From NCERT
AIPMT - 2010
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Which of the following pairs has the same size?

1. Fe2+, Ni2+

2. Zr4+, Ti4+

3. Zr4+, Hf4+

4. Zn2+, Hf4+

Subtopic:  d-Block Elements- Properties & Uses |
 88%
From NCERT
AIPMT - 2010
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Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states?

1. 3d3, 4s2

2. 3d5, 4s1

3. 3d5, 4s2

4. 3d2, 4s2

Subtopic:  d-Block Elements- Properties & Uses |
 80%
From NCERT
AIPMT - 2009
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Which one of the following ions is the most stable in an aqueous solution? 
(At. No. Ti = 22, V = 23, Cr = 24, Mn = 25)

1. Cr3+

2. V3+

3. Ti3+

4. Mn3+

Subtopic:  d-Block Elements- Properties & Uses |
From NCERT
AIPMT - 2007
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The d-electron configurations of Cr2+, Mn2+, Fe2+ and Ni2+ and 3d4, 3d5, 3d6 and 3d8 respectively.
Which one of the following aqua complexes will exhibit the minimum paramagnetic behaviour? 
(At. No. Cr = 24, Mn = 25, Fe = 26, Ni = 28)

1. \(\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
2. \(\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
3. \(\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
4. \(\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

Subtopic:  d-Block Elements- Properties & Uses |
 72%
From NCERT
AIPMT - 2007
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The manganate and permanganate ions are tetrahedral, due to:

1. The π-bonding involves the overlap of d-orbitals of oxygen with d-orbitals of manganese.
2. The π-bonding involves the overlap of p-orbitals of oxygen with d-orbitals of manganese.
3. Absence of π-bonding.
4. The π-bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese.
Subtopic:  Chemistry of Mn and Cr Compounds |
 74%
From NCERT
NEET - 2019
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Actinoids exhibit more number of oxidation states than lanthanoids. It is because of: 
1. The greater metallic character of the lanthanoids than that of the corresponding actinoids.
2. More energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals.
3. The lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals.
4. More active nature of the actinoids.
Subtopic:  d-Block Elements- Properties & Uses | f-Block Elements- Properties & Uses | Lanthanoid & Actinoids Contraction |
 79%
From NCERT
AIPMT - 2011
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For the four successive transition elements (Cr, Mn, Fe and Co), the stability of +2 oxidation state will be there in which of the following order? 
(At. No Cr= 24, Mn= 25, Fe=26, Co= 27)

1.  Fe>Mn>Co>Cr

2.  Co>Mn>Fe>Cr

3.  Cr>Mn>Co>Fe

4.  Mn>Fe>Cr>Co

Subtopic:  d-Block Elements- Properties & Uses |
 65%
From NCERT
AIPMT - 2011
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