d and f Block Elements · Chemistry · COMEDK
MCQ (Single Correct Answer)
Identify the correct statement from the following.
An inorganic compound $$\mathrm{W}$$ undergoes the following reactions:
$$ \begin{gathered} W+\frac{\mathrm{Na}_2 \mathrm{CO}_3}{\mathrm{O}_2 / \text { heat }} \rightarrow X+\frac{\mathrm{H}^{+}}{} \rightarrow Y_{(s)} \\ Y(a q)+\mathrm{KCl}(\mathrm{aq}) \rightarrow Z_{(S)} \end{gathered} $$
Z appears in the form of orange crystals and is used as an oxidising agent in acid medium. Identify the compound W.
The Lanthanoid ion which would form coloured compounds is -------------.
Atomic numbers: $$\mathrm{Yb}=70, \quad \mathrm{Lu}=71, \mathrm{Pr}=59, \quad \mathrm{La}=57$$
The metallic ions that have almost same spin only magnetic moment are :
(i) $$\mathrm{Co}^{2+}$$
(ii) $$\mathrm{Mn}^{2+}$$
(iii) $$\mathrm{Cr}^{2+}$$
(iv) $$\mathrm{Cr}^{3+}$$
The correct order of increasing melting point is
Consider the following statements in respect of lanthanides, which of the statements are incorrect?
(i) $$\mathrm{La}(\mathrm{OH})_3$$ is least basic among the hydroxides of lanthanides
(ii) The lanthanide ions $$\mathrm{Yb}^{2+}, \mathrm{Lu}^{3+}$$ and $$\mathrm{Ce}^{4+}$$ are diamagnetic in nature.
(iii) $$\mathrm{Ce}^{4+}$$ can act as an oxidising agent
(iv) $$\operatorname{Ln}$$ (III) compounds are generally colourless
(v) Ionic radii of $$\mathrm{Ce}^{3+}$$ is greater than $$\mathrm{Yb}^{3+}$$
Arrange the following ions in the increasing order of their $$\Delta H_{(\text {hydration})}$$ values.
$$\mathrm{Cr}^{2+}, \mathrm{Co}^{2+}, \mathrm{Mn}^{2+}, \mathrm{Ni}^{2+}$$
The permanganate ion in acid medium acts as an oxidant and gets converted to its lower oxidation state. What would be the spin only magnetic moment of such reduced manganese ion?
Match the compounds given in Column I with their characteristic features listed in Column II
| No. | Column I | No. | Column II |
|---|---|---|---|
| A | $$ \mathrm{La}(\mathrm{OH})_3 $$ |
P | Acidic in nature |
| B | $$ \mathrm{Mn}_2 \mathrm{O}_7 $$ |
Q | Least basic |
| C | $$ \mathrm{Lu}(\mathrm{OH}) 3 $$ |
R | Interstitial compound |
| D | $$ \mathrm{Fe}_3 \mathrm{H} $$ |
S | Most basic |
Choose the incorrect statement from the following
$$\mathrm{Ti}^{2+}$$ is purple while $$\mathrm{Ti}^{4+}$$ is colourless because
A volatile compound is formed by carbon monoxide and
Match the following characteristics of transition metals given in Column I with the examples listed in Column II
| S. No. | Characteristic properties | S. No. | Examples |
|---|---|---|---|
| W | Chemically inert, non-stoichiometric compound | A | $$\mathrm{WO}_3$$ |
| X | Higher oxidation states are more stable | B | $$\mathrm{TiCl_4}$$ |
| Y | Due to inert pair effect, lower oxidation state is more stable | C | $$\mathrm{Mn_4N}$$ |
| Z. | Colourless compound of transition metal | D | $$\mathrm{SnCl_2}$$ |
Find the correct matches of the substances, given in Column I, from their characteristic properties given in Column II.
| S.No. | Column I | S.No. | Column II |
|---|---|---|---|
| W | $$ \mathrm{Tl} $$ |
A | Decomposes steam to form its dioxide and dihydrogen gas. |
| X | $$ \mathrm{CCl}_4 $$ |
B | Consists of twenty 6 -membered rings and twelve 5 membered rings. |
| Y | $$\mathrm{Tin}$$ | C | +3 oxidation state is highly oxidising. |
| Z | $$ \mathrm{C_{60}} $$ |
D | Electron precise species, neither acts as electron donor nor as electron acceptor. |
Identify the incorrect statement.
An aqueous solution of X on addition of hydrogen peroxide in ice cold conditions gives blue colour to the ethereal layer. Then, X can be
In 3d-transmission series, which one has the least melting point?
The electronic configuration of Cr$$^{3+}$$ is
Formation of coloured solution is possible, when metal ion in the compound contains
Which of the following forms a colourless solution in aqueous medium?