13
MCQ (Single Correct Answer)
Gadolinium belongs to 4 f series. Its atomic number is 64 . Which of the following is the correct electronic configuration of gadolinium?
A
$[\mathrm{Xe}] 4 f^7 5 d^1 6 s^2$
B
$[\mathrm{Xe}] 44^6 5 d^2 6 s^2$
C
$[\mathrm{Xe}] 4 f^8 6 d^2$
D
$[\mathrm{Xe}] 4 f^9 5 s^1$
14
MCQ (Single Correct Answer)
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
A
They have high melting points in comparison to pure metals
B
They are very hard
C
They retain metallic conductivity
D
The are chemically very reactive
15
MCQ (Single Correct Answer)
The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of $\mathrm{Cr}^{3+}$ ion is
A
2.87 BM
B
3.87 BM
C
3.47 BM
D
3.57 BM
16
MCQ (Single Correct Answer)
$\mathrm{KMnO}_4$ acts as an oxidising agent in alkaline medium. When alkaline $\mathrm{KMnO}_4$ is treated with KI , iodide ion is oxidised to ........... .
A
$\mathrm{I}_2$
B
$\mathrm{IO}^{-}$
C
$\mathrm{IO}_3^{-}$
D
$\mathrm{IO}_4^{-}$
17
MCQ (Single Correct Answer)
Which of the following statements is not correct?
A
Copper liberates hydrogen from acids
B
In its higher oxidation states, manganese forms stable compounds with oxygen and fluorine
C
$\mathrm{Mn}^{3+}$ and $\mathrm{Co}^{3+}$ are oxidising agents in aqueous solution
D
$\mathrm{Ti}^{2+}$ and $\mathrm{Cr}^{2+}$ are reducing agents in aqueous solution