COMEDK · Chemistry · 23. d and f Block Elements
Identify the correct statement from the following.
- A \(\mathrm{Cr}(\mathrm{VI})\) is more stable than \(\mathrm{W}(\mathrm{VI})\) and hence acts as a good oxidising agent
- B Interstitial compounds of transition metals have lower melting points than that of pure transition metals and their compounds are chemically reactive
- C Cerium is a lanthanoid metal which exists in a stable oxidation state of +4 , besides exhibiting an oxidation state of +3
- D The green manganate ion shows diamagnetic nature but the permanganate ion exhibits paramagnetic nature
Answer & Solution
Correct Answer
(C) Cerium is a lanthanoid metal which exists in a stable oxidation state of +4 , besides exhibiting an oxidation state of +3
Step-by-step Solution
Detailed explanation
Correct answer: (3) (1) Incorrect: Higher oxidation states become more stable down the group, so W(VI) is more stable than Cr(VI). Cr(VI) is less stable and hence acts as a strong oxidising agent. (2) Incorrect: Interstitial compounds have higher melting points than pure metals…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- Structures of 3 Monosaccharides are given below. Two of them are Anomers. Identify the two Anomers.
COMEDK 2023 Medium - Which of the following is always true about a spontaneous cell reaction in a galvanic cell?COMEDK 2026 Medium
- Which one of the following is the correct statement?COMEDK 2025 Easy
- Horn silver isCOMEDK 2019 Easy
- Arrange the following redox couples in the increasing order of their reducing strength:
\(\begin{array}{ll}
{[\mathrm{A}]=\mathrm{Cu} / \mathrm{Cu}^{2+}} & \mathrm{E}^0=-0.34 \mathrm{~V} \\
{[\mathrm{~B}]=\mathrm{Ag} / \mathrm{Ag}^{+}} & \mathrm{E}^0=-0.8 \mathrm{~V} \\
{[\mathrm{C}]=\mathrm{Ca} / \mathrm{Ca}^{2+}} & \mathrm{E}^0=+2.87 \mathrm{~V} \\
{[\mathrm{D}]=\mathrm{Cr} / \mathrm{Cr}^{3+}} & \mathrm{E}^0=+0.74 \mathrm{~V}
\end{array}\)COMEDK 2024 Medium - Which of the following statements is incorrect?COMEDK 2016 Easy
More PYQs from COMEDK
- A sonometer string vibrates with a frequency of 400 Hz . When the length of the string is halved and the tension is altered, it begins to vibrate with a frequency of 200 Hz . The ratio of the new tension to the original tension in the string is:COMEDK 2025 Medium
- The square of resultant of two equal electric field vectors is three times their product. Angle between them isCOMEDK 2025 Easy
- The length of the latus rectum of a conic \(49 y^2-16 x^2=784\) isCOMEDK 2025 Easy
- \(1 \mathrm{~cm}^3 \text { of } 0.01 \mathrm{~M} \mathrm{~HCl} \text { is added to } 1 \mathrm{~L} \text { of } \mathrm{NaCl} \text { solution. The } \mathrm{pH} \text { of the resulting solution is: }\)COMEDK 2024 Medium
- The points on the \(x\)-axis whose perpendicular distance from the line \(\dfrac{x}{3}+\dfrac{y}{4}=1\) is 4 units areCOMEDK 2024 Medium
- The diagram shows a barrel of weight \(1.0 \times 10^{3} \mathrm{~N}\) on a frictionless slope inclined at \(30^{\circ}\) to the horizontal.
The force is parallel to the slope. What is the work done in moving the barrel a distance of \(5.0 \mathrm{~m}\) up the slope?COMEDK 2015 Hard