{"question": "Which of the following statements about the lanthanide elements is NOT true?", "options": ["The most common oxidation state for the lanthanide elements is +3.", "Lanthanide complexes often have high coordination numbers (> 6).", "All of the lanthanide elements react with aqueous acid to liberate hydrogen.", "The atomic radii of the lanthanide elements increase across the period from La to Lu."], "answer": "D"}
{"question": "A 0.217 g sample of HgO (molar mass = 217 g) reacts with excess iodide ions according to the reaction shown above. Titration of the resulting solution requires how many mL of 0.10 M HCl to reach equivalence point?", "options": ["1.0 mL", "10 mL", "20 mL", "50 mL"], "answer": "C"}
{"question": "Predict the number of lines in the EPR spectrum of a solution of 13C-labelled methyl radical (13CH3\u2022), assuming the lines do not overlap.", "options": ["4", "3", "6", "24"], "answer": "A"}
{"question": "3 Cl\u2212(aq) + 4 CrO_4^2\u2212(aq) + 23 H+(aq) \u2192 3 HClO2(aq) + 4 Cr3+(aq) + 10 H2O(l). In the reaction shown above, Cl\u2212(aq) behaves as", "options": ["an acid", "a base", "a catalyst", "a reducing agent"], "answer": "D"}
{"question": "Which of the following lists the hydrides of group-14 elements in order of thermal stability, from lowest to highest?", "options": ["PbH4 < SnH4 < GeH4 < SiH4 < CH4", "PbH4 < SnH4 < CH4 < GeH4 < SiH4", "CH4 < SiH4 < GeH4 < SnH4 < PbH4", "CH4 < PbH4 < GeH4 < SnH4 < SiH4"], "answer": "A"}