The coloured compound among the following in the solid state is-
1. \( \mathrm{Ag}_{2} \mathrm{SO}_{4} \)
2. \(\mathrm {C u F}_{2} \)
3. \(\mathrm {Zn F}_{2} \)
4. \(\mathrm{Cu}_{2} \mathrm{Cl}_{2} \)

On addition to a small amount of KMnO₄ to concentrated H₂SO₄, a green oily compound is obtained which is highly explosive in nature. Identify the compound from the following.

1. Mn₂O₇

2. MnO₂

3. MnSO₄

4. Mn₂O₃

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of the transition element, which shows the highest magnetic moment.

$1. 3d^7$
$2. 3d^5$
$3. 3d^8$
$4. 3d^2$

Which of the following oxidation state is common for all lanthanoids?

1.  +2

2.  +3

3.  +4

4.  +5

Which of the following reactions are disproportionation reactions?

$\left(i\right) C{u}^{+} \to C{u}^{2+} + Cu$
$$
$\left(ii\right) 3Mn{O}_4^{-} + 4H^{+} \to 2MN{O}_4^{-} + Mn{O}_2 + 2H_{2}O$
$$
$\left(iii\right) 2KMn{O}_4 \to K_{2}Mn{O}_4 + Mn{O}_2 + O_2$
$$
$\left(iv\right) 2Mn{O}_4^{-} + 3M{n}^{2+} + 2H_{2}O \to 5Mn{O}_2 + 4H^{+}$

1.  (i)

2.  (i) , (ii) and (iii)

3.  (ii) , (iii) and (iv)

4.  (i) and (iv)

When $KMn{O}_4$ solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because

1.  $C{O}_2$ is formed as the product

2.  Reaction is exothermic

3.  $Mn{O}_4^{-}$ catalyses the reaction

4.  $M{n}^{2+}$ acts as autocatalyst

There are 14 elements in the actinoid series. Which of the following elements does not belong to this series?

1. U

2. Np

3. Tm

4. Fm

$KMn{O}_4$ acts as an oxidizing agent in an acidic medium. The number of moles of $KMn{O}_4$ that will be needed to react with one mole of sulphide ions in an acidic solution is$\mathrm{:}$
1. \(\frac{2}{5}\)
2. \(\frac{3}{5}\)
3. \(\frac{4}{5}\)
4. \(\frac{1}{5}\)

Which of the following is amphoteric oxide ?

$1. V_2{O}_5 , C{r}_2{O}_3$
$2. M{n}_2{O}_7 , Cr{O}_3$
$3. CrO , V_2{O}_5$
$4. V_2{O}_5 , V_2{O}_4$

Gadolinium (atomic number 64) belongs to the 4f series.
The correct electronic configuration of gadolinium among the following is:

\(1. (X e) 4 f^{7} 5 d^{1} 6 s^{2} \)

2. \( (X e) 4 f^{6} 5 d^{2} 6 s^{2}\)

3. \((X e) 4 f^{8} 6 d^{2}\)

4. \((X e) 4 f^{9} 5 s^{1}\)