12th Grade > Chemistry
D AND F BLOCK ELEMENTS MCQs
Total Questions : 43
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Answer: Option C. -> Mn>Cr>Fe>Co
:
C
E0 values of M2+/M with negative sign are: Cr=-0.91V, Mn= -1.18V, Fe=-0.44V,Co= -0.28V. Thus, the order is Mn>Cr>Fe> Co.
:
C
E0 values of M2+/M with negative sign are: Cr=-0.91V, Mn= -1.18V, Fe=-0.44V,Co= -0.28V. Thus, the order is Mn>Cr>Fe> Co.
Answer: Option B. -> Y3+
:
B
Y belongs to 5th period & La belongs to 6th period. Ionic radii increases from Y3+toLa3+ down the group. Due to lanthanoid contraction, ionic radii follows the order
Lu3+<Eu3+<La3+
:
B
Y belongs to 5th period & La belongs to 6th period. Ionic radii increases from Y3+toLa3+ down the group. Due to lanthanoid contraction, ionic radii follows the order
Lu3+<Eu3+<La3+
Question 3. Read the assertion and reason carefully to mark the correct option out of the options given below:
(a)If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b)If both assertion and reason are true but reason is not the correct explanation of the assertion.
(c)If assertion is true but reason is false.
(d)If assertion is false but reason is true.
Assertion: Ionisation enthalpies for early actinoids are lower than that for early lanthanoids.
Reason: 5f electrons more effectively shielded from the nuclear charge than the 4f electrons
of the corresponding lanthanoids.
(a)If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b)If both assertion and reason are true but reason is not the correct explanation of the assertion.
(c)If assertion is true but reason is false.
(d)If assertion is false but reason is true.
Assertion: Ionisation enthalpies for early actinoids are lower than that for early lanthanoids.
Reason: 5f electrons more effectively shielded from the nuclear charge than the 4f electrons
of the corresponding lanthanoids.
Answer: Option A. -> a
:
A
Although the 5forbitals resemble the 4forbitals in their angular part of the wave-function, they are not as buried as 4forbitals and hence 5felectrons are less firmly heldin actinoids.
:
A
Although the 5forbitals resemble the 4forbitals in their angular part of the wave-function, they are not as buried as 4forbitals and hence 5felectrons are less firmly heldin actinoids.
Answer: Option C. -> VOSO4
:
C
V+4→3d14s0
1 unpaired electrons. Hence, it is paramagnetic and coloured compound.
:
C
V+4→3d14s0
1 unpaired electrons. Hence, it is paramagnetic and coloured compound.
Answer: Option C. -> In the Wacker process the oxidation of ethyne to ethanal is catalysed by Hg2Cl2.
:
C
- In the Wacker process the oxidation of ethyne to ethanal is catalysed by PdCl2
:
C
- In the Wacker process the oxidation of ethyne to ethanal is catalysed by PdCl2
Answer: Option A. -> [Cr(NH3)6]+3
:
A
All metal carbonyls are diamagnetic cyanide complexes are also diamagnetic. Cyanide ion and Carbonyls are strong field ligands causing d-orbital electrons of metal ion to pair up.
:
A
All metal carbonyls are diamagnetic cyanide complexes are also diamagnetic. Cyanide ion and Carbonyls are strong field ligands causing d-orbital electrons of metal ion to pair up.
Answer: Option B. -> Mn2+ and Fe3+
:
B
Mn2+ and Fe3+ ions have 23 electrons, thus, they are isoelectronic.
:
B
Mn2+ and Fe3+ ions have 23 electrons, thus, they are isoelectronic.
Answer: Option C. -> TiF2−6 and Cu2Cl2
:
C
Co−ordinationcomplexMetalionUnpairedelectronsinmetalionNatureofcomplexCoF3−6Co3−4ParamagneticNiCl2−4Ni2+2ParamagneticTiF2−6Ti4+0DiamagneticCu2Cl2Cu+0Diamagnetic
:
C
Co−ordinationcomplexMetalionUnpairedelectronsinmetalionNatureofcomplexCoF3−6Co3−4ParamagneticNiCl2−4Ni2+2ParamagneticTiF2−6Ti4+0DiamagneticCu2Cl2Cu+0Diamagnetic
Answer: Option D. -> 4 f sub shell- half filled
:
D
Gd= 4f75d16s2;Gd3+=4f7
:
D
Gd= 4f75d16s2;Gd3+=4f7
Answer: Option A. -> orange-red
:
A
The aqueous blue solution of CuSO4 absorbs orange-red colour of light
:
A
The aqueous blue solution of CuSO4 absorbs orange-red colour of light