23
MCQ (Multiple Correct Answer)
Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
A
$\mathrm{Co}^{2+}$
B
$\mathrm{Cr}^{2+}$
C
$\mathrm{Mn}^{2+}$
D
$\mathrm{Cr}^{3+}$
24
MCQ (Multiple Correct Answer)
In the form of dichromate, $\mathrm{Cr}(\mathrm{VI})$ is a strong oxidising agent in acidic medium but $\mathrm{Mo}(\mathrm{VI})$ in $\mathrm{MoO}_3$ and W (VI) in $\mathrm{WO}_3$ are not because
A
$\mathrm{Cr}(\mathrm{VI})$ is more stable than $\mathrm{Mo}(\mathrm{VI})$ and $\mathrm{W}(\mathrm{VII})$.
B
$\mathrm{Mo}(\mathrm{VI})$ and $\mathrm{W}(\mathrm{VI})$ are more stable than $\mathrm{Cr}(\mathrm{VI})$.
C
Higher oxidation states of heavier members of group-6 of transition series are more stable.
D
Lower oxidation states of heavier members of group-6 of transition series are more stable.
25
MCQ (Multiple Correct Answer)
Which of the following actinoids show oxidation states upto +7 ?
A
Am
B
Pu
C
U
D
Np
26
MCQ (Multiple Correct Answer)
General electronic configuration of actinoids is $(n-2) \mathrm{f}^{1-14}(\mathrm{n}-1) \mathrm{d}^{0-2} \mathrm{~ns}^2$. Which of the following actinoids have one electron in 6d orbital?
A
U (Atomic number. 92)
B
Np (Atomic number. 93)
C
Pu (Atomic number. 94)
D
Am (Atomic number. 95)
27
MCQ (Multiple Correct Answer)
Which of the following lanthanoids show +2 oxidation state besides the characteristic oxidation state +3 of lanthanoids?
A
Ce
B
Eu
C
Yb
D
Ho