COMEDK 2024 Evening Shift | d and f Block Elements Question 2 | Chemistry

$$ \begin{gathered} W+\frac{\mathrm{Na}_2 \mathrm{CO}_3}{\mathrm{O}_2 / \text { heat }} \rightarrow X+\frac{\mathrm{H}^{+}}{} \rightarrow Y_{(s)} \\ Y(a q)+\mathrm{KCl}(\mathrm{aq}) \rightarrow Z_{(S)} \end{gathered} $$

Z appears in the form of orange crystals and is used as an oxidising agent in acid medium. Identify the compound W.

$$\mathrm{K}_2 \mathrm{CrO}_4$$

$$\mathrm{FeCr}_2 \mathrm{O}_4$$

$$\mathrm{Cu}(\mathrm{CrO}_2)_2$$

$$\mathrm{Na}_2 \mathrm{CrO}_4$$

COMEDK 2024 Evening Shift

MCQ (Single Correct Answer)

-0

The Lanthanoid ion which would form coloured compounds is -------------.

Atomic numbers: $$\mathrm{Yb}=70, \quad \mathrm{Lu}=71, \mathrm{Pr}=59, \quad \mathrm{La}=57$$

$$Y b^{2+}$$

$$L a^{3+}$$

$$L u^{3+}$$

$$\operatorname{Pr}^{3+}$$

COMEDK 2024 Morning Shift

MCQ (Single Correct Answer)

-0

Arrange the following ions in the increasing order of their $$\Delta H_{(\text {hydration})}$$ values.

$$\mathrm{Cr}^{2+}, \mathrm{Co}^{2+}, \mathrm{Mn}^{2+}, \mathrm{Ni}^{2+}$$

$$ \mathrm{Co}^{2+}<\mathrm{Ni}^{2+}<\mathrm{Cr}^{2+}<\mathrm{Mn}^{2+} $$

$$ \mathrm{Cr}^{2+}<\mathrm{Mn}^{2+}<\mathrm{Co}^{2+}<\mathrm{Ni}^{2+} $$

$$ \mathrm{Ni}^{2+}<\mathrm{Co}^{2+}<\mathrm{Mn}^{2+}<\mathrm{Cr}^{2+} $$

$$ \mathrm{Mn}^{2+}<\mathrm{Cr}^{2+}<\mathrm{Co}^{2+}<\mathrm{Ni}^{2+} $$

COMEDK 2024 Morning Shift

MCQ (Single Correct Answer)

-0

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?

2.84 BM

4.90 BM

3.87 BM

5.92 BM

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