21
MCQ (Single Correct Answer)
Why is HCl not used to make the medium acidic in oxidation reactions of $\mathrm{KMnO}_4$ in acidic medium?
A
Both HCl and $\mathrm{KMnO}_4$ act as oxidising agents
B
$\mathrm{KMnO}_4$ oxidises HCl into $\mathrm{Cl}_2$ which is also an oxidising agent
C
$\mathrm{KMnO}_4$ is a weaker oxidising agent than HCl
D
$\mathrm{KMnO}_4$ acts as a reducing agent in the presence of HCl
22
MCQ (Multiple Correct Answer)
Generally transition elements and their salts are coloured due to the presence of unpaired electrons in metal ions. Which of the following compounds are coloured?
A
$\mathrm{KMnO}_4$
B
$\mathrm{Ce}\left(\mathrm{SO}_4\right)_2$
C
$\mathrm{TiCl}_4$
D
$\mathrm{Cu}_2 \mathrm{Cl}_2$
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