Lanthanoids and lanthanoid contraction

28 questions on Lanthanoids and lanthanoid contraction from the d- and f-Block Elements chapter: 6 NEET level, 11 JEE Main, 11 JEE Advanced. Each one opens with its answer and solution.

• The electrons that are added progressively on moving from Ce to Lu enter the NEET level
• The most common and characteristic oxidation state of the lanthanoids is NEET level
• Lanthanoid contraction is mainly caused by NEET level
• Among the following, the lanthanoid that commonly shows the +4 oxidation state in addition to +3 is NEET level
• Misch metal, an alloy used in making flints and in alloy steels, consists mostly of lanthanoid metals together with about 5% of NEET level
• Among the following aqueous tripositive ions, the one that is colourless is NEET level
• In acidic solution Ce^4+ is a strong oxidising agent even though it has the stable 4f^0 configuration. The best explanation is that JEE Main level
• Aqueous Eu^2+ (4f^7) slowly reduces H^+ in dilute acid. The balanced ionic equation with the product in its characteristic state is JEE Main level
• Assertion (A): The atomic radii of Zr and Hf are almost equal. Reason (R): The 4f electrons shield the nuclear charge poorly across the lanthanoid series. Choos... JEE Main level
• Match the ions in Column I with their 4f configurations in Column II. Column I: P = Ce^3+, Q = Eu^3+, R = Gd^3+, S = Yb^3+. Column II: 1 = 4f^1, 2 = 4f^6, 3 = 4... JEE Main level
• Among the following hydroxides, the most basic is JEE Main level
• Two lanthanoids show anomalously large metallic radii compared with their neighbours, because they use only two electrons per atom in metallic bonding, retainin... JEE Main level
• Among the following neutral gaseous atoms (atomic numbers in brackets), the one whose ground-state configuration contains a 5d electron is JEE Main level
• Lanthanoid metals react with hot water. The balanced equation, with the metal in its characteristic oxidation state, is JEE Main level
• Which of the following tripositive ions has the largest number of unpaired electrons? JEE Main level
• The element samarium has atomic number 62. Find the number of unpaired electrons in the Sm^3+ ion (give the answer as an integer). JEE Main level
• Which of the following statements are correct? JEE Main level
• A lanthanoid has atomic number 64 and the ground-state configuration [Xe]4f^75d^16s^2. The spin-only magnetic moment (in BM) of its tripositive ion is closest t... JEE Advanced level
• For which of the following pairs of ions is the spin-only magnetic moment identical? (Atomic numbers: Ce 58, Nd 60, Sm 62, Eu 63, Gd 64, Dy 66, Ho 67) JEE Advanced level
• A yellow acidic solution of Ce^4+ is treated with excess Fe^2+ in dilute sulfuric acid. The cerium species present at the end, and its magnetic character, are JEE Advanced level
• Hafnium (Z = 72) has nearly the same atomic radius as zirconium (Z = 40), although it has 32 more electrons and one more shell. The correct reasoning is JEE Advanced level
• Assertion (A): Among the lanthanoids, Ce and Tb are the two whose +4 state is most commonly met in solid compounds, such as CeO2 and TbO2. Reason (R): Ce^4+ and... JEE Advanced level
• Match the ions in Column I with their spin-only magnetic moments (BM) in Column II. Column I: P = Ce^3+ (Z = 58), Q = Nd^3+ (Z = 60), R = Sm^3+ (Z = 62), S = Gd... JEE Advanced level
• Which of the following are consequences of lanthanoid contraction? JEE Advanced level
• Z values: Eu = 63, Gd = 64, Tb = 65. Which of the following species have exactly seven unpaired electrons? JEE Advanced level
• Take these standard potentials in acidic solution: Ce^4+/Ce^3+ = +1.61 V, Fe^3+/Fe^2+ = +0.77 V, H^+/H2 = 0.00 V, Eu^3+/Eu^2+ = -0.35 V, Yb^3+/Yb^2+ = -1.05 V. ... JEE Advanced level
• Terbium has atomic number 65 and ground-state configuration [Xe]4f^96s^2. Calculate the spin-only magnetic moment of Tb^4+ in BM, using mu=sqrtn(n+2) (answer to... JEE Advanced level
• Which statements about ground-state atoms are correct? JEE Advanced level